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<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Robotic Misdirection, For Good Causes</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Max Fowler fowlml</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>@students .ipfw.edu</string-name>
          <email>thieac01@students</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="editor">
          <string-name>Artificial General Intelligence; AI; Deception; Automatic
Prover; Cognitive Event Calculus</string-name>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Aaron Thieme .ipfw.edu</institution>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Analogical Constructivism and Reasoning Lab Department of Computer Science Indiana University-Purdue University Fort Wayne</institution>
          ,
          <country country="US">USA</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2017</year>
      </pub-date>
      <fpage>47</fpage>
      <lpage>54</lpage>
      <abstract>
        <p>Deception is a core component of human interaction and reasoning, and despite its negative connotation, it can be used in positive ways. We present our formalization behind strategic deception, one such potentially positive form of deception. We use the Cognitive Event Calculus (CEC) to model strategic deception, building on prior formalizations. First, we provide a brief overview of deception's definitions within existing literature. Following this discussion, CEC is described and we present CEC-style inference rules for strategic deception. These rules and a positive motivating deception example are used to show how we can solve the problem of strategic deception. This proof is demonstrated both through application of our rules and by adapting our rules for MATR (Machina Arachne Tree-based Reasoner) to show how proving can be performed by automatic reasoners. Finally, we discuss what future steps can be taken with strategic deception.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>INTRODUCTION</title>
      <p>
        One ultimate goal of Artificial General Intelligence (AGI)
is to finally bridge the gap between man and machine and
create systems capable of human level thought and
reasoning. Waser’s work aiming to clarifying AGI as a field
postures that the positive goal of AGI is that human style
reasoning systems will be universal problem solvers for the
world [
        <xref ref-type="bibr" rid="ref23">23</xref>
        ]. Some approaches to AGI take a formalized
mathematical basis, such as Hutter’s AIXI agent used to model
artificial death by Martin et. al. [
        <xref ref-type="bibr" rid="ref14">14</xref>
        ]. Others take the
approach that we should develop computational logics which
provide reasoning strong enough to model human level
reasoning and hopefully not see us all be killed, as Bringsjord
argued [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ]. This paper takes the latter approach, oe↵ring
a formalization of a wonderfully human action - strategic
deception.
      </p>
      <p>
        Lying and deceiving are quintessential elements of human
reasoning and interaction. Hippel and Trivers consider
deception, and specifically the co-evolution between deceivers
and those who are deceived, to be a major contributing
factor to the evolution of human intelligence [
        <xref ref-type="bibr" rid="ref22">22</xref>
        ]. This makes
having a formalization for deception ideal, such that we may
better understand our own cognitive systems. Further, an
understanding of deception opens the kinds of interactions
we can model for the field of artificial general intelligence. A
greater wealth of interactions will hopefully allow for more
advances in the field.
      </p>
      <p>
        Deception is often considered negative (e.g. lying to one’s
wife about a mistress, deceiving one’s boss about work
accomplished, tax evasion), yet deception does have positive
benefits. Many of these benefits exist in the field of creating
artificially intelligent systems to assist humans. Sakama
describes a medical assistant that may not always tell patients
the truth, much like doctors must sometimes practice
deception in their bedside manner to keep patients calm [
        <xref ref-type="bibr" rid="ref18">18</xref>
        ].
Another medical example includes a diagnosis robot.
Assume there is a minuscule chance of a patient having lupus
and treating lupus will kill that particular patient for some
reason if that patient does not have lupus. It would be ideal,
then, for a medical diagnosis robot to not inform the doctor
about the small chance of the disease being lupus until other
options are exhausted.
      </p>
      <p>
        It is further reasonable to think of cases where a deceptive
artificial agent can provide more security than other agents,
to the benefit of humans. Consider the case of an
artificial generally intelligent robot guarding a school’s research
lab. The robot has a key to access the lab, knows all the
members of the lab, and is instructed to avoid conflict when
dealing with potential intrusions into the lab. A student of
ill morals approaches the robot, intent on gaining entry to
the lab by lying about being a lab member’s friend.
Logically, it would be well within the robot’s rights to tell the
individual to leave. However, this goes against the
directive to avoid conflict, as a rude response could result in the
would-be thief becoming desperate, violent, or more
scheming in response. We wish to give our robot agent the ability
to deceive the thief into believing the robot is unable to help
them directly by lying that it does not have the lab key
anymore. This provides a safer, more diplomatic di↵usion of the
situation. In what manner, then, can we teach our agents
how to deceive, like a human could, to avoid this conflict?
Deception is well agreed upon as requiring success to be
called such [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ]. Lying is generally accepted as requiring the
statement of a belief that is false to the speaker [
        <xref ref-type="bibr" rid="ref13">13</xref>
        ]. These
agreements serve as a cornerstone for the formalization of
deception but are unsatisfying in their abstractness. Other
researchers have attempted to define specific requirements
for deception and lies to function. Forbus argues that
deception necessarily assaults agents’ predictive abilities and
argues for an analogical reasoning approach towards
understanding the mechanism of deception [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ]. Stokke argues for
the assertion model of lying and claim that assertions should
be used to create common ground. This common ground
provides a shared set of beliefs between agents that is
pivotal for lying to proceed [
        <xref ref-type="bibr" rid="ref20">20</xref>
        ]. Chisholm and Feehan add that
lies necessitate that the liar wish for their lie to be believed
by another [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ].
      </p>
      <p>
        Multiple formalizations exist for various forms of
deception and deceptive situations. Sakama creates a general
formalization of deception, based on van Ditsmarch’s
formalization of lying; Sakama calls this the agent
announcement framework [
        <xref ref-type="bibr" rid="ref18 ref21">18, 21</xref>
        ]. The work provides a solid
backbone for formalizing general deception but can be
notationally unintuitive. Licato’s work showed how the modal logic
based cognitive event calculus (CEC) can be used to
elegantly model the nested layers of beliefs required to perform
the deception shown in the show Breaking Bad, in a
fashion that lends itself well to automatic reasoners [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ]. There
exists room to marry the eciency in modeling provided by
CEC with rules designed specifically to formalize deception,
similar to the work of Sakama and van Ditsmarch.
      </p>
      <p>We present a CEC formalization for deception while
defining strategic deception. First, we will present the definition
of deception and strategic deception we will use in this
paper. Then, we define the problem of strategic deception:
what is necessary for strategic deception, why it is useful,
and what the success and failure conditions are. Following,
we formalize our reasoning approach by expanding upon CEC
with new inference rules. As an aside, we develop forms of
Sakama’s deception rules, translating from the agent
announcement framework to CEC. Finally, we show how by
using CEC and MATR (Machina Arachne Tree-based
Reasoner), an automatic reasoning system, an artificial generally
intelligent agent can reason over the lab guarding situation
and successfully di↵use the issue.
2.</p>
    </sec>
    <sec id="sec-2">
      <title>DEFINING DECEPTION AND STRATE</title>
    </sec>
    <sec id="sec-3">
      <title>GIC DECEPTION</title>
      <p>
        Before defining strategic deception, we must present the
definition of general deception this paper uses. The OED
defines deception by saying that it is “to cause to believe what
is false” [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. Mahon’s work rejects this as too simple, as it
allows for mistaken deception and inadvertent deception [
        <xref ref-type="bibr" rid="ref13">13</xref>
        ].
Mistaken deception concerns cases where an agent leads
another to believe a false formula that the agent itself believes.
A recent example of inadvertent deception can be found in
the striped dress which led the internet to debate, “Is this
dress white and gold or black and blue?” [
        <xref ref-type="bibr" rid="ref17">17</xref>
        ]. Mahon’s
presents a traditional definition of deception, D1, that
requires deception to be an intentional act: “To deceive ==df
to intentionally cause to have a false belief that is known or
believed to be false” [
        <xref ref-type="bibr" rid="ref13">13</xref>
        ]. We prefer to align ourselves with
Mahon’s D2, though, as it restricts the deception to only
cases where the deceiver causes the deception, rather than
a third party or outside force: “A person x deceives another
person y if and only if x causes y to believe p, where p is
false and x does not believe that p is true.” This definition
is most in agreement with Sakama’s definition of deception,
which is part of what we will use to define strategic
deception [
        <xref ref-type="bibr" rid="ref18">18</xref>
        ]. By default, this definition does not require a
lack of truthfulness, which means one can deceive by telling
the truth. This definition also has no requirement for
making statements, which means non-verbal communication and
even non-communication, such as placing a briefcase in a
room, can be used to deceive.
      </p>
      <p>
        We define strategic deception as a specialized form of
Chisholm and Feehan’s positive deception simpliciter, the
form of deception in which one agent contributes to another
acquiring a belief [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ]. In strategic deception, the deceiving
agent must want something of another agent: generally, to
act upon or in-line with the deceiver’s goal. This goal can
be in a negative form (e.g. I do not want this agent to eat
my sandwich). We define a strategically deceptive agent as
follows:
(SD) An agent a is strategically deceptive to
another agent b IFF agent a causes b to believe ,
where is false and a believes that is false, by
causing b to believe some false statement ,
selected such that believing requires b to develop
belief in , using some strategy to accomplish an
overall goal .
      </p>
      <p>
        In order for an agent to be deceptive in a general sense,
there are a number of conditions that must be met. Sakama
agrees with the common contention that deception, by
definition, requires success [
        <xref ref-type="bibr" rid="ref18">18</xref>
        ]. We include this in our
definition of strategic deception. Castelfranchi’s earlier work on
deception requires that the addressee believes the speaker is
attempting to benefit or assist them, and thus be
trustworthy, and believe that the agent is not ignorant [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ]. Further,
McLeod’s summarized definition of trustworthiness requires
vulnerability on the part of the addressee, requires some
assumed competence on the part of the speaker, and requires
that the addressee think well of the speaker within some
context [
        <xref ref-type="bibr" rid="ref16">16</xref>
        ]. For this paper, we assume trust is given unless
a deception is caught, as the establishment of trust is not
within our scope.
      </p>
      <p>
        Deception functions die↵rently in regards to di↵erent kinds
of agents. Sakama’s formalization of deception primarily
focuses on credulous agents, which are defined in the agent
announcement framework as agents who believe the speaker
is sincere [
        <xref ref-type="bibr" rid="ref18 ref21">18, 21</xref>
        ]. We consider it unlikely that deceiving
credulous agents is worth investigating, as such agents are
bound by their nature to adopt any belief directed at them.
For our purposes, we are more concerned with the agent
announcement framework’s skeptical agent: in brief, skeptical
agents are belief consistent agents, only adding beliefs to
their belief set that are consistent. We refer to Sakama’s
skeptics as maximally belief consistent agents, to avoid
confusing them with other definitions of skepticism.
      </p>
      <p>
        Strategic deception requires that our agent lie. That is,
agent a must believe some statement , yet act as if they
believe ¬ . The agent announcement framework ’s set up for
a lie based deception requires that the listener come to
believe a false statement , based on the idea of believing the
speaker is truthful. That is, justifies belief in to agent b.
We adopt the directionality that justif ies . This more
naturally opens up the ways our agents can lie. For
example, while it is possible that a can literally say implies ,
lies by omission are desirable. Consider the case of eating a
coworker’s sandwich and being accused after the act.
Saying, ”The fact that I am a vegetarian means Bob, and not I,
must have eaten your ham sandwich,” may convince the
accuser. However, just saying ”I’m a vegetarian,” implies that
one could not have eaten a ham sandwich. Further, saying,
”I’m a vegetarian, but I saw Bob near the fridge earlier,”
accomplishes the same thing at the first sentence without
directly lying. If a lie is by omission, it is not involved in
the dialogue and may be harder to pick up on. This makes
our overall deception hard for agent b to check, which is one
of the conditions put forward for the successful selection of
lies by Forbus [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ]. In the sandwich example, if we never
mention the possibility of eating the sandwich at all, agent
b may simply not think about that possibility and blame
Bob instead. This certainly holds true for maximally belief
consistent agents, in the event Bob eating the ham sandwich
is a reasonable explanation: we remove the alternative that
we ate the sandwich completely.
      </p>
      <p>In Section 3, we discuss how we know strategic deception
has succeeded and how strategies for deception are designed.
In Section 4 and onward, we discuss our formalization and
how we use rules to prove deception.
3.</p>
    </sec>
    <sec id="sec-4">
      <title>HOW WE KNOW WE</title>
    </sec>
    <sec id="sec-5">
      <title>HAVE STRATEGICALLY DECEIVED</title>
      <p>Strategic deception requires the creation of a strategy.
This strategy is made up of the statements agent a can make
in order to deceive agent b. In order to form a strategy, we
must know the domain of our situation. More specifically,
a must know the domain they are using to deceive b. The
domain includes a, b, and any other entities who may be
related to this particular school lab or the lab’s parent
department. It further includes beliefs a has about these traits
and beliefs a believes b has. For our original example, some
domain beliefs are believing the department has a secretary,
believing that secretary helps students, and believing that r
helps students and secretaries. From the domain, then, we
create a strategy consisting of our goal , a generated to
justify our lie, and any supporting µ statements we wish to
use.</p>
      <p>Strategic deception necessitates the generation of a false
statement by the speaker. The selection of an
appropriate is a dicult quandary. We do not make an e↵ort to
rate specific against each other within the same domain
directly. Instead, we concern ourselves only with ensuring a
is an appropriate choice. To determine if a false statement
is appropriate for a given deception, we consider the set
P = p1, ..., pi of all beliefs related to the situation agent b
holds. A simple heuristic, then, allows us to rapidly rule out
candidate s.</p>
      <p>removal heuristic 1: if P [ { } ` q for an
arbitrary q, is unfit to choose as the false statement
justification for our deceptive agent’s lie due to
being contradictory to b’s beliefs.</p>
      <p>Finalizing the selection of which an agent decides to say
is more dicult that ruling out bad . A good must help
advance the deceiving agent’s goal. That is, belief that
justifies should lead to an agent acting upon the deceiver’s
goal . This leads to a second heuristic for selection.</p>
      <p>removal heuristic 2: if the chosen does not
lead to the deceived agent acting upon , then
the is unfit to choose for justification as its
selection does not lead to success.</p>
      <p>As a final consideration for generation, we need to
consider how a is actually formed. Without bounding what
information an agent can use to generate a , we risk
allowing an agent too much information that may not be relevant
to the problem at hand, which may bog the decision
making process down significantly. Therefore, we require that
a given be chosen only if it is within the domain of the
strategic deception being carried out. This domain includes
traits about the situation, such as the location and agents
involved, as well as the speaker ’s beliefs and beliefs about
the addressee’s beliefs. An example of a domain is defined
along with our proof further on.</p>
      <p>This same domain is useful for the generation or
recruitment of supporting µns. All supporting statements must
lend credence to and must belong to the same domain
as . Ocially, this means that any given µ is selected in
order to make believable to an addressee, and thus allow
for deception to proceed. For the belief consistent agents
we use, this is suciently handled by requiring any chosen
µ makes belief consistent with the addressee’s belief set.
Recruitment of µns can be carried out by a adopting beliefs
it thinks b has. Generation, meanwhile, should merge facts
traits from the domain with either beliefs a has or a believes
b has or with lies or blu↵s that are consistent with b’s
beliefs. To provide a set heuristic for ruling out µ options, we
use:
µ removal heuristic: if the chosen µ does not help
lead to the deceived agent believing , then the
µ is unfit to choose as the justification as it does
not lead to success.</p>
      <p>One way to consider µ in a general sense is to consider
µ’s relevance. In that respect, the above heuristic can be
summed up as the relevance of the belief in µ in regards to
the belief in .</p>
      <p>
        Strategic deception also requires an established
mechanism for asserting beliefs and establishing common grounds.
Stokke contends that lying requires some assertion from
speaker to addressee [
        <xref ref-type="bibr" rid="ref20">20</xref>
        ]. We address this in our inference
rules later on using CEC S operator. We wish to point out
that here, we operate with S in the linguistic sense of stating
sentences. It is sucient for words to be used in the
communication, but they can be spoken or written. Non-verbal
addressing is acceptable for general deception and assertion,
as supported by Chisholm’s formative work [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ]. Stokke
further mandates that common ground between speaker and
addressee are required for deception to succeed [
        <xref ref-type="bibr" rid="ref20">20</xref>
        ]. We
agree, as this is consistent with Sakama’s belief consistent
agents. This is further consistent with requiring belief
consistent agents be made to believe the speaker believes what
they are asserting for deception to succeed [
        <xref ref-type="bibr" rid="ref18">18</xref>
        ]. This is why
later on, we require agent a to not only make agent b believe
the lies but also make agent b believe that agent a believes
the lies as well.
      </p>
      <p>It is important to consider the success and failure
conditions for strategic deception in some detail. As most work
on deception requires, we require strategic deception to be
successful. Further, as strategic deception is goal motivated,
a’s goal must be met. Strategic deception fails, then, in the
following situations:
1. A given ¬ or ! ¬ fails to be consistent with b’s
beliefs and b rejects a’s trustworthiness as a result,
believing they are being lied to
2. A failure of the deception due to irrationality on b’s
behalf
3. A failure of the strategy used if b is successfully
deceived yet does not act in the way a intends</p>
      <p>Case (1) is a clear cut failure of deception. Case (2) is
trickier. We define irrationality on agent b’s behalf as agent
b rejecting, rather than adopting, a belief consistent belief
they are exposed to. This still means the deception fails,
and thus agent a was not deceptive. However, we wish to
make clear that agent a’s strategies do not fail in (2). An
agent practicing perfect strategic deception can always fail
through no fault of their own in the event of (2) occurring.
Finally, case (3) is interesting in that it is a failure not of the
deception, but of the strategy used. The strategy is defined
as the selection of and supporting µs, as well as any other
steps taken during the strategic deception process. If agent b
comes to be deceived, yet does not act as agent a intends (or
does not act at all), agent a has failed. This makes strategic
deception potentially more flimsy than general deception, as
agent b’s inaction results in a’s failure.
4.</p>
    </sec>
    <sec id="sec-6">
      <title>FORMALIZING LIES AND DECEPTION</title>
      <p>IN CEC</p>
      <p>
        We begin by describing CEC. Arkoudas and Bringsjords’
cognitive event calculus (CEC) is a first-order modal logic
framework that expands upon Kowalski’s event calculus [
        <xref ref-type="bibr" rid="ref10 ref4">4,
10</xref>
        ]. The event calculus itself is a first-order logic with types.
It features actions, or events, to represent actions that occur.
Fluents are used to represent values which can change over
time and can be propositional or numerical in nature. Time
is represented with timepoints which can be either
continuous or discrete. In summary, the event calculus is used to
model how events a↵ect fluents through time, allowing for
the modeling of event chains [
        <xref ref-type="bibr" rid="ref19">19</xref>
        ].
      </p>
      <p>The event calculus models these event chains through the
acts of clipping and starting fluents through events. If a
fluent exists and has not been clipped (ended or stopped by
an action) at a time t, then it is said the fluent holds at t.
For any time t, a fluent will hold for that time so long as
it has yet to be clipped. Events, then, are responsible for
both initiating fluents and clipping them. An event chain
can trace how a fluent is e↵ected by the events occurring to
it.</p>
      <p>
        CEC creates an event calculus for cognition. It uses modal
operators for belief (B), knowledge (K), and intent (I). CEC
avoids possible-world semantics, in favor of a more
computationally reasonable proof-theoretical approach. An attempt
is made to model natural deduction as closely as possible, to
best represent human-style reasoning [
        <xref ref-type="bibr" rid="ref15">15</xref>
        ]. Two of the most
important departures CEC has are as follows:
• CEC’s inference rules and logical operators are restricted
to the contexts for which they are defined, to prevent
problems that can occur with overreaching rules.
• Underlying inferences use constantly refined inference
rules. This is used instead of cognitively implausible
strategies, despite the latter having some potential use.
      </p>
      <p>
        The CEC formulae tend to include an agent, a time, and a
nested formula. When agent a believes at time t, we write
B(a, t, ). Similar syntax is used to say an agent perceives,
(P),knows (K), an agent says something (S). There are some
special operators that do not follow this trend. C is used
to establish a common belief, while S has a directed syntax
for agent a to declare a formula to agent b. Intention is
handled as an intent to perform an action. While an agent
can intend to act at time t, the intention identifies a time t0
when that intention will be acted on. CEC uses happens as
an operator to launch an action [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ].
      </p>
      <p>
        CEC also addresses the idea of agents being able to
perform actions, using a↵ordances. A↵ordances are actions an
agent can perform starting at a time t. All possible
actions an agent can take are the agent’s ao↵rdance set. We
say isAf f ordance(action(a, ), t) when at time t, and
beyond agent a can perform that action. This was added to
CECto allow belief creation to be handled on an a↵orded
basis, rather than on an immediate basis following logical
closure [
        <xref ref-type="bibr" rid="ref11">11</xref>
        ]. As a further trait of CEC, actions tend to require
the happens operator. For example, happens(a, t, act( ))
means that at time t, it happens that a has performed the
act action on some formula . If a instead intends to
perform that action, the following syntax is used: happens(a, t,
intends(a, t, act( ))).
      </p>
      <p>In the rules below, we introduce a supports operator.
This operator conveys that the first argument causes the
second to become believable. For a maximally belief
consistent agent, if µ supports , then that simply means that µ
is consistent with b’s beliefs and then allows to be
consistent. Much like justif ies, there is room to grow supports
for die↵rent kinds of agents, in regards to relatedness and
similar factors, that is not addresses in this paper’s scope.</p>
      <p>Moving on, we set out to model deception in CEC . We
start our formalization by converting some of Sakama’s
deception axioms to CEC . We leave most of the nuances of the
Sakama’s framework out of this paper, though we do walk
our readers through two of Sakama’s axioms. First, consider
Sakama’s A2, the axiom covering a liar’s understanding of
their having lied:
(A2)[¡a ]Ba ⌘</p>
      <p>Ba¬</p>
      <p>Ba[¡a ]
(1)</p>
      <p>The agent announcement framework, while concise, can
be dicult to expand. The left hand side says that after
a’s lying announcement of , agent a believes . The right
hand side of the equivalence is the implication that if agent
a believes ¬ , then agent a believes that after their lying
announcement of , is true. The essential component of
this rule, in regards to the modal CEC, is that when agent a
lies about , they believe is true. One problem here is the
implicit assumption that ¬ leads to . We will later handle
this assumption through the use of a justifies operator.</p>
      <p>As a second example, consider Sakama’s A5, the axiom
covering a credulous agent being lied to:
(A5)[¡a ]Bb ⌘</p>
      <p>Ba¬</p>
      <p>Bb[!a ]
(2)</p>
      <p>Axiom A5 means the following: After a’s lying
announcement of , agent b believes . This is equivalent to the
imSyntax</p>
      <sec id="sec-6-1">
        <title>Object|Agent|ActionType|Action v Event|</title>
        <p>S ::= Moment|Boolean|Fluent|Numeric
action : Agent ⇥ ActionType ! Action
initially : Fluent ! Boolean
holds : Fluent ⇥ Movement ! Boolean
happens : Event ⇥ Movement ! Boolean
clipped : Movement ⇥ Fluent ⇥ Movement ! Boolean
f ::= initiates : Event ⇥ Fluent ⇥ Movement ! Boolean
terminates : Event ⇥ Fluent ⇥ Movement ! Boolean
prior : Movement ⇥ Movement ! Boolean
interval : Movement ⇥ Boolean
payo↵ : Agent ⇥ ActionType ⇥</p>
      </sec>
      <sec id="sec-6-2">
        <title>Movement ! Numeric</title>
        <p>t::=x : S |c : S |f (t1, ..., tn)</p>
        <p>t : Boolean |¬ | ^ | _ |8 x : S. |9 x : S.
::= P(a, t, ) |K(a, t, ) |C(t, ) |S(a, b, t, ) |S(a, t, )
B(a, t, ) |I(a, t, happens(action(a⇤ , ↵ ), t0 ))
plication that if agent a believes ¬ , then agent b believes
that after agent a’s truthful announcement of , b believes
. Implicit to this rule is that agent b believes that agent a
has told the truth in regards to , as is a trait of credulous
agents. This is sucient for modeling lying and deception in
a general sense. We will adapt this rule to work with
maximally belief consistent agents, to add a bit more challenge
to strategic deception over convincing a gullible agent.</p>
        <p>
          For deception, we introduce an operator justifies. The
justifies operator is used to indicate when one formula justifies
another formula within a context. This is similar to
justification logics, which unwrap modal belief operators into
the form p: X, where, “reason p justifies X,” [
          <xref ref-type="bibr" rid="ref2">2</xref>
          ]. Our form
of justification changes based upon the agent being
considered. For our maximally belief consistent agents, justifies
is the same as ! implication on a belief level. That is, if
B(b, t, justif ies( , ), then B(b, t, B(b, t, ) ! B(b, t, )).
This would not be true for other agents, safe a belief
relevant maximizer. In that case, we would need to consider
relevance, as well as belief implication. We adopt this form
of flexible justifies to allow flexibility in modeling. For our
purposes, the justifies provided above is enough. Given this,
a strategically deceptive agent must be certain that any
they choose is functional justification for the reasoning
performed by b.
4.1
        </p>
        <p>Deception CEC Rules</p>
        <p>We provide a set of inference rules used to prove a case of
strategic deception. These rules are designed for strategic
deception cases similar to our motivating example in the
intro. We assume a necessity for our speaker to state the lie,
as well as the generated false . Further, we desire rules that
allow for the use of supporting µs as desired.The candidate
rules appear in Figure 2. These rules do not broach the
subject of and µ generation, as this is out of the scope of
our paper.</p>
        <p>An intent to deceive is required, formalized as an action
using the deceives formula. ID acts as the beginning
inference rule to establish that deception is desired. This is done
primarily to ease ending the proof - a’s intent to deceive
must be acknowledge for deception to succeed. The formula
takes an agent as the target for the deception and a formula
as the deception’s goal.</p>
        <p>We have BDP and BDPS as two forms of beginning
deception, once the intent is formed. We have two forms of
this rule to allow for the deceptive agent to decide to say
and for the deceptive agent to decide to state the
justification with . These rules make use of the S operator from
CECto dictate how and when agents speak. They also use
the D and I to show agent a’s desire to deceive with goal
and show that a’s intent is to have agent b carry out ,
respectively. A causes operator is used to link believing a
formula (the first argument) to acting on another (the
second argument).</p>
        <p>
          MBCA shows how maximally belief consistent agents come
to adopt beliefs they find consistent with their belief set.
This uses the isBeliefConsistent rule from earlier work by
Licato [
          <xref ref-type="bibr" rid="ref11">11</xref>
          ]. JBA establishes the mechanism by which µs
can be used to support a by causing to become belief
consistent with a given agent’s belief set. SP establishes a
rule that mandates supporting with a µ if such a µ exists.
BCI establishes that an agent who believes the lie from the
deception and believes that lie causes an action develops an
intent to take that action.
        </p>
        <p>Finally, SSD establishes a successful deception. The
reasoning is simple: if the target agent acts on the goal as
desired, the strategic deception is successful. Rules for the
failure cases are not provided here, for simplicity’s sake.</p>
        <p>With a set of inference rules established, we may proceed
to prove our deception example from earlier.</p>
      </sec>
    </sec>
    <sec id="sec-7">
      <title>PROVING STRATEGIC DECEPTION</title>
      <p>Let us return to our motivating example. We have a robot,
agent r, confronted by the would-be malicious thief, agent
b. Agent b wishes to get into the lab, asking about , agent
r having the key to the lab. Agent r must output ¬ and
justif ies ¬ such that r follows the rules of strategic
deception: r ’s creation or recruitment of must not jeopardize
r ’s ⌧ in regards to b and must be consistent with b’s beliefs.
(10) happens(b, t3, intends(b, t1, ))
(11) happens(b, t4, )
(10);b performs intention
(12) happens(r, t, didDeceive(b)
5.1</p>
    </sec>
    <sec id="sec-8">
      <title>Showing Strategic Deception in MATR</title>
      <p>With our inference rules developed and a proof provided
above, we use MATR to automate our reasoning. MATR is
a joint production by the Rensselaer Polytechnic Institute’s
Further, if possible, agent r must output a series of
statement µ1...µn such that each µ supports . For the strategic
deception to be successful, r must succeed in their goal of
making b believe r no longer has the key and leaving r alone,
having either given up or decided to pursue a di↵erent agent
for questioning.</p>
      <p>Strategic deception requires r to know the domain of the
situation. In this example, the domain includes r, b, and any
other entities who may be related to this particular school
lab or the lab’s parent department. It further includes
beliefs r has about these traits and r believes b has. Some
example beliefs are believing the department has a
secretary, believing that secretary helps students, and believing
that r helps students and secretaries.</p>
      <p>From this information, r must generate a strategy to use
to carry out the deception. For our paper’s example, we
assign the following as sample, acceptable values for each
sentence used in our strategic deception proof:</p>
      <p>= Agent r wants agent b to stop asking
questions about the lab to r
¬</p>
      <p>= Agent r does have the key
= Agent doesn’t r has the key
= Agent r gave the lab key to the building’s
secretary
µ1 = The secretary needed the lab key to help
students get access to the lab</p>
      <p>We start our proof by assuming r begins with the belief ¬
and the intent to deceive for . For this proof, we assume
that the use of µ1 is not necessary, as b adopts upon
hearing it in accordance with the MBCA rule. Further, we
do not cite a specific rule for agent b acting on an intention.
(1) B(r, t, ¬ )
(2) happens(r, t, intends(r, t, deceive(b, )))
;assumption
(3) B(r, t, causes(,
)) ^ B(b, t, causes(,
)) ;assumption
(4) generated , such that it justifies
(5) generated µ1
(6) D(r, t, holds(B(b, t1, ), t1))
(7) I(r, t, happens(b, t1, ))
(8) S(r, b, t1, )
(9) B(b, t2, )
;assumption
;assumption
;assumption
(1),(2),(3);ID
(1),(2),(3);ID
(4),(6),(7);BDPS
(8);MBCA</p>
      <p>
        (9);BCI
(11);SSD ⇤
(a) A figure of the finished proof in MATR. The top left shows the steps taken,
while the bottom right provides a codelet execution log.
(b) The MATR diagram represents codelets and the suppositions as
boxes. The circles represent the actual formulae. Circle 1 represents
our conclusion.
Rensselaer AI and Reasoning (RAIR) lab and Indiana
University Purdue University’s Analogical Constructivism and
Reasoning Lab (ACoRL) [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ]. It is an argument-theoretic
reasoner developed in Java to use codelets, small,
specialized programs, to solve a proof in a step-by-step process.
A codelet manager module is in charge of deciding which
codelets are best suited for a proof and what codelet results
to use as steps in the proof. Once a proof is found, MATR
generates a box diagram of the proof. Figure 3a shows our
strategic deception proof entered into MATR and Figure 3b
shows the proof diagram. Antecedents are made up of all
assumptions and beginning information for our proof, while
the conclusion is our final step of showing our deception’s
success. MATR’s rule syntax is slightly adjusted for ease of
entry into the Java program. For example, the assumption
B(r, t, ¬ ) becomes (B r t (neg phi)). Formulae are nested
within the parenthesis and commas are removed. For ease
of following the MATR codelets, the codelets used share
the same name as the inference rules used, with some small
exceptions. Some rules are used in MATR that were not
specifically provided, such as one which links intent to
acting (denoted ITA).
      </p>
    </sec>
    <sec id="sec-9">
      <title>CONCLUSION AND FUTURE WORK</title>
      <p>We set out to create a formalism for strategic deception.
We began by establishing the definition of deception we
adopted and defined strategic deception on top of that. Then,
we provided an overview of CEC and our formalism for
strategic deception. A discussion on creating a strategy for
such deception, as well as the cases in which strategic
deception can be said to fail, followed. Our formalized rules
were used to perform a proof on our motivating example
of strategic deception and were shown to be functional in</p>
      <p>MATR.</p>
      <p>It is our hope that this paper provides three major
contributions. First, that the idea of strategic deception proves
useful to the field of formalizing deception as a whole with
new inference rules and perspectives. Second, that our work
furthers the field of formalization for artificial general
intelligence. As we build our formalization of the way humans
think and reason, we can further our progress to true AGI,
if such a thing is even possible to achieve. Third, ideally
the work shown in CEC will allow others, both related to
RAIR and ACoRL and outside our institutions, to continue
to build on the strength of CEC’s rule set. CEC grows more
robust through continued applications and new
formalizatons. We further hope this paper serves as a small
acknowledgment of the ease of developing codelets for MATR.</p>
      <p>This paper is far from an exhaustive take on deception in
CEC. Room exists to consider other forms of agents, such
as agents which require statement relevancy in order to be
willing to accept beliefs. The scope of such agents was
outside of this introductory paper to strategic deception.
Further, other forms of deception exist. Strategic deception
was a fairly niche focus. From the work of Chisholm alone,
there exist many other directions to develop specialized
deceptions. As an example, one could investigate the kind of
agent who means well, but perpetually deceives others by
telling the truth in a decidedly unusual way: an unlucky
truth-telling agent, perhaps.</p>
      <p>This paper also leaves some concepts incomplete. The
generation of and µ are not addressed in this paper. This
may be best accomplished using data processing outside of
MATR, such as using more standard machine learning
techniques. This may also be a case for further refinement of
CEC style inference rules and codelets, specifically to
generate that information. The development of such processes,
and discussions of them, we defer to future work from the
ACoRL and other organizations.</p>
      <p>Further, justif ies and supports as used within the paper
are to a degree naive. We used them entirely for maximally
belief consistent agents and did not spend much time
discussing them. A whole paper could, and perhaps should, be
written on the idea of belief justification and belief
supporting in CEC.</p>
      <p>Finally, more examples are needed to test and refine the
inference rules put forward in this paper. A CEC rule is only
as strong as the proofs which use it successfully. Further,
with more proofs and sample situations will come more rule
refinement. Within our motivating example alone, there is
room to explore di↵erent situations: cases where µ is needed,
cases where deception fails, cases where deception succeeds
but a strategy fails. We defer these discussions for future
papers, but hope we have provided the cornerstone in our
work.</p>
      <p>There is plenty of room to expand the set of rules
provided in this paper into a larger suite of strategic deception
rules, or even a suite of CEC general deception rules. More
dicult situations must be considered, including situations
of multiple deception attempts chaining into each other. In
the future, we hope to present one such example using the
social strategy party game Mafia, testing our strategic
deception formalism in a competitive group setting. A social
strategy game provides a strong testbed of interaction and
deception.
7.</p>
    </sec>
  </body>
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    </ref-list>
  </back>
</article>