Programming Interactive Worlds with Linear Logic

Ph.D. thesis defense

Transcript

1. 1
2. 2
3. 3 Attack (Starts at 1) Health (Starts at 3)
4. 4 Buff: Add 1 to attack
5. 5 Attack: Enemy subtracts your attack from their health
6. 6 Yellow Team Go! BUFF ATTACK
7. 7 Buff other: Spend your turn to increase someone else’s attack
8. 8 Blue Team Go! BUFF (self or other) ATTACK
9. 9
10. 10
11. 11
12. 12 PROBLEM
13. 13 Formal Language for Game Sketching Executable Rules First Platform-agnostic General
14. 14 Formal Language for Game Sketching Executable Rules First Platform-agnostic General
15. 15 Formal Language for Game Sketching Executable Rules First Platform-agnostic General
16. 16 Formal Language for Game Sketching Executable Rules First Platform-agnostic General
17. 17 Interactive Worlds (Definition) An interactive world is an initial configuration (e.g. your cards at the start of the game) ! together with rules for evolving configurations, (e.g.: buffing increases your attack) ! some of which are mediated by human interaction, randomness, or other processes.
18. 18
19. 19 A formal language for describing interactive worlds makes it easier to sketch and invent novel game & story designs. Thesis Statement (Take 1)
20. 20 Thesis Statement (Take 1) A formal language for describing interactive worlds makes it easier to sketch and invent novel game & story designs.
21. 21 Authoring Potential Narratives [Diagram credit: Sam Kabo Ashwell]
22. 22 Authoring Potential Narratives
23. 23 Authoring Potential Narratives choose character stats branch on character stats
24. 24 A formal language for describing interactive worlds enables rapid prototyping of experimental game designs and deeper understanding of narrative structure. Thesis Statement (Take 2)
25. 25 Thesis Statement (Take 2) A formal language for describing interactive worlds enables rapid prototyping of experimental game designs and deeper understanding of narrative structure.
26. 26 THESIS STATEMENT Using linear logic to model interactive worlds enables rapid prototyping of experimental game designs and deeper understanding of narrative structure.
27. Programming language (Ceptre) Causal analysis for games & narratives Case studies Meta-reasoning methodology 27 Contributions
28. 28 Programming language (Ceptre) Causal analysis for games & narratives Case studies Meta-reasoning methodology Contributions
29. 29 APPROACH Linear Logic Programming
30. 30 Logic Facts about the world are propositions: ! The player is in the foyer Juliet loves Romeo Roger has 2 health points
31. 31 Facts about the world are propositions: ! ! ! Logic
32. 32 Action and Change
33. 33 Action and Change [Girard 1987, Girard/LaFont 87, Chang et al. 2003]
34. 34
35. 35
36. 36 Movement rule, take 2
37. 37
38. 38
39. 39 Movement rule, take 3
40. 40 Movement rule, take 3’
41. 41 Program Rules move : in player Room * adjacent Room Room’ —o in player Room’. ! adjacent/foyer-kitchen : adjacent foyer kitchen.
42. 42 Author-defined terms and predicates, quantified Variables, tensor (*), bang (!), and lolli (—o) are all we need to specify action & change on a logical level. Linear Logic
43. 43 A * $B —o C ! == ! A * B —o C * B Derived Syntax
44. 44 Programming language (Ceptre) Causal analysis for games & narratives Case studies Meta-reasoning methodology Contributions
45. 45 Linear Logic Programming Configuration (linear context) term/predicate declarations,
 permanent facts, and rules [Harland et al. 2000; Lopez et al. 2005] e.g. Signature (permanent rules)
46. 46 Multiset Rewriting [Cervesato & Scevdrov 2009] (synonym: forward chaining)
47. 47 EXAMPLE WORLD: Defense Defense
48. 48 Buffing buff : turn Player * attack Player Att -o attack Player (Att + 1).
49. 49 Buffing Others buff : turn Player * attack Player’ Att -o attack Player’ (Att + 1).
50. attack : turn Player * $attack Player A * health Enemy H -o health Enemy (H - A). ! die : health P 0 -o dead P. 50 Attacking
51. 51 Configurations (Contexts) { turn player1, turn player4, […], on_team player1 blue, on_team player2 yellow, health player1 3, attack player2 2, […] } Multisets of ground propositions
52. 52 Running a program context init = {…} #trace init. 0
53. 53 Running a program Quiescence: no more rules in can fire 0 … n
54. 54 Prior linear logic programming languages: Celf, LolliMon, Lygon Ceptre: Adding Interactivity and Stages
55. 55 stage yellow_team = { attack : … buff : … } ! stage blue_team = { attack : … buff : … }
56. 56 stage play = { attack : … buff : … } ! stage generate_turns = { … }
57. 57 stage play = { attack : … buff : … } ! qui * stage play * team_turn T * opp T T’ -o stage generate_turns * team_turn T. ! stage generate_turns = { … } ! qui * stage generate_turns -o stage play.
58. 58 stage play = { attack : … buff : … } #interactive play. ! ! ! stage generate_turns = { … }
59. 59 0: (quiesce) 1: (buff chris 1) 2: (buff andre 1) […] 7: (target chris yellow blue frank 1 3) 8: (target chris yellow blue gwenn 1 3) ! ?-
60. 60 Ceptre Persistent backward-chaining Linear forward-chaining Terms, predicates Stages and quiescence rules (Sensing and acting predicates) http://www.github.com/chrisamaphone/interactive-lp Chapter 4 - AIIDE 2015
61. 61 Ceptre Compilable to Celf via interleaved (linear) backward and forward chaining http://www.github.com/chrisamaphone/interactive-lp Chapter 4 - AIIDE 2015
62. Programming language (Ceptre) Causal analysis for games & narratives Case studies Meta-reasoning methodology 62 Contributions
63. 63 63 Proof Construction
64. 64 64
65. 65 65
66. 66 66
67. 67 67
68. 68 68
69. 69 Concurrent Structure let b = r1 a1 let c = r2 a2 a1 a2 = b c let b = r1 a1 let c = r2 a2
70. 70 Concurrent Structure r1 c r2 b a1 a2
71. 71 Causal Structure attack buff die buff
72. 72 TAKEAWAY: Concurrent structure in proofs yields causal structure among actions [Bosser et al. 2010, 2011; Watkins et al. 2002]
73. Programming language (Ceptre) Causal analysis for games & narratives Case studies Meta-reasoning methodology 73 Contributions
74. 74 Case Study: Shakespearean Tragedy Story World do/becomeSuicidal : at C L * depressed C * depressed C * depressed C * depressed C -o at C L * suicidal C * wants C weapon.
75. 75 Causal Structure do/murder romeo capulet town do/insult/private tybalt town montague do/becomeSuicidal montague town do/m juliet tow do/suicide romeo town x147 do/mourn montague town romeo x154 x153 x152 x151 x155 x182 x188 x187 x186 x185 x184 x198 x197 x196 x200 x199
76. 76 init emmaSpendsYearsInCovent leonFallsInLove emmaReadsRomanticNovels emmaReadsRomanticNovels emmaMarriesCharles emmaInvitedToBall emmaDiscoversLeonsLove emmaPushesLeonAway emmaContractsDebts emmaDoesNotGoToBall rodolpheDecidesToSeduceEmma emmaAcceptsRodolpheAdvances emmaContractsDebts rodolpheRelationshipFalters charlesDecidesToOperateHypolyte hypolyteIsAmputated emmaPurchasesGift emmaOffersGift emmaPurchasesProstheticLeg rodolpheBreaksUp emmaJumpsThroughWindow OR Causal Structure
77. 77 Narrative Generation Chapter 3/INT 2014/LPNMR 2013
78. 78
79. 79 Tamara
80. 80 Tamara
81. 81 ! b9_aelis_monologue : aelis b9 diningroom -o aelis c12 atrium. ! b10_dante_despiga : dante b10 atrium * despiga b10 atrium -o dante c12 atrium * despiga c12 atrium. ! b11_dannunzio_luisa : dannunzio b11 dannunzioroom * luisa b11 dannunzioroom -o dannunzio c12 atrium * luisa c12 above-atrium.
82. 82 x12 a1_dannunzio_exits x17 x16 a1_grp2_aelis b4_carlotta_kisses_finzi x20 x19 x18 b2_despiga_monologue a1_grp1_luisa x22 x21 b9_aelis_monologue a1_grp2_emilia x23 b10_dante_despiga x25 x24 b3_luisa_monologue a1_grp1_dannunzio x2 x26 x27 c12_finzi_exit x28 b11_dannunzio_luisa x30 a1_emilia_exits x32 x31 b6_dannunzio_monologue x33 x34 x36 x35 x37 x39 x38 b7_emilia_monologue x41 x40 x42 b8_emilia_carlotta x44 x43 b5_finzi_monologue x46 x45 x47 x53 x51
83. 83 a1_emilia_exits a1_dannunzio_exits x14 a1_grp1_dannunzio x16 a1_grp2_emilia b2_despiga_monologue a1_grp2_aelis a1_grp1_luisa x23 b10_dante_despiga x25 x24 b3_luisa_monologue x28 x27 b6_dannunzio_monologue x30 x29 c12_finzi_exit x31 b11_dannunzio_luisa x32 b4_carlotta_kisses_finzi x35 x34 b9_aelis_monologue x36 x38 x37 b7_emilia_monologue x39 x41 x40 c_final x43 x42 b8_emilia_carlotta b5_finzi_monologue x44 x45 x47 x46 c12_gunshot x53 x52 x51 x50 x49 x48 c12_emilia_carlotta_aelis_luisa_leave_atrium c12_take_presents_to_leda x56 x55 x54 c13_finzi_luisa_confrontation x60 x59 x58 x57 c13_emilia_aelis_carlotta_luisa_sidehall x62 x61 x66 x65 x64 x63 x70 x69 x68 x67 c14_emilia_enter_leda x74 x73 x72 x71 c14_all_exit_leda x78 x77 x76 x75
84. 84 Interactive World Case Studies Chapter 5 Interactive storytelling (BuffyWorld) Action/reaction model ! ! ! !
85. 85 Interactive World Case Studies Chapter 5 Interactive storytelling (BuffyWorld) Action/reaction model ! Board/card games: die rolls and distribution ! !
86. 86 Interactive storytelling (BuffyWorld) Action/reaction model ! Board/card games: die rolls and distribution ! Novel designs: generative simulation games (RPG and GardenSim worlds) Interactive World Case Studies Chapter 5
87. 87 Limitations? Negation Comprehension Rule ordering etc.
88. 88 Limitations? Programming Tricks (see Chapter 4) Negation Comprehension Rule ordering etc.
89. 89 Fun with Ceptre Debugging automatic/generative stages Experimenting with player control schemes
90. 90 Fun with Ceptre “Fuzz testing” player input Augmenting rules w/AI strategies
91. buff : turn Player * $on_team Player T * $on_Team Player’ T * attack Player’ Att -o attack Player’ (s Att). 91 Augmenting rules with strategies: Buffing Only Friends
92. attack : turn Player * $on_team Player Team * opp Team Team’ * $on_team Enemy Team’ * $attack Player Att * health Enemy H -o subtract Enemy H Att. 92 Augmenting rules with strategies: Attacking Only Enemies
93. 93 Fun with Ceptre Evaluating for Balance
94. 94 (Actual) Limitations buff : turn Player * attack Player A -o attack Player (A+1). Invariants: each player should only ever have 1 turn active ! a character should either be dead or have a team ! a character with a team should always have an attack value ! …
95. 95 Contributions Programming language (Ceptre) Causal analysis for games & narratives Case studies Meta-reasoning methodology
96. 96 (Chapter 6) Reasoning Framework
97. 97 Program Invariants INV holds of all initial configurations; ! and for all rules and all contexts , ! whenever INV holds of sdfa ! ! INV holds of j Invariant INV holds for a specification iff:
98. 98 Propositional Ceptre (similar to Horn clauses): ! ! ! where can be atoms a or !a. Program Invariants
99. 99 Generative invariants (Simmons ’12) Program Invariants = =
100. 100 Decidability Result Via vector addition systems, the problem can be reduced to Presburger arithmetic (known decidable.) Upshot: Whether or not a given (propositional Ceptre) program satisfies a flat invariant is decidable.
101. 101 DISCUSSION
102. 102 To PL theory: Better understanding of forward-chaining logic programming Theoretical result about checking properties of evolving systems Large base of application examples ! To game & narrative design: Better understanding of structure for potential narratives Unification of rule languages for narratives and systems Sandbox for prototyping, analyzing, and iterating upon designs Thesis Contributions
103. 103 Future Work Narrative representation: modal and higher-order logics (character-based reasoning about other characters’ beliefs; theory of mind) ! Automated reasoning tools ! Accessible game design framework
104. 104 Thesis Statement, reprise Ceptre (Ch 4) Reasoning Tools (Ch 6) Using linear logic to model interactive worlds enables rapid prototyping of experimental game designs and deeper understanding of narrative structure.
105. 105 Thesis Statement, reprise Using linear logic to model interactive worlds enables rapid prototyping of experimental game designs and deeper understanding of narrative structure. Case Studies (Ch 5)
106. 106 Thesis Statement, reprise Chapters 2 & 3 Using linear logic to model interactive worlds enables rapid prototyping of experimental game designs and deeper understanding of narrative structure.
107. Thanks! Using linear logic to model interactive worlds enables rapid prototyping of experimental game designs and deeper understanding of narrative structure. Thesis Statement, reprise http://www.cs.cmu.edu/~cmartens/thesis.pdf
108. 108 Bonus Slides
109. 109 Backward chaining (goal directed) ! vs ! Forward chaining (context-directed)
110. 110 Backward Chaining
111. 111 Backward Chaining
112. 112 Backward Chaining
113. 113 Forward Chaining
114. 114 Forward Chaining
115. 115 Forward Chaining
116. 116 Forward Chaining
117. attack : turn Player * $on_team Player Team * opp Team Team’ * $on_team Enemy Team’ * $attack W Att * health Enemy H * nat_minus H Att H’ -o health Enemy H’. ! die : health P z -o dead P. 117 Backward-Chaining Subtraction
118. 118 } Prove with goal-directed rules } Find in linear context attack : turn Player * $on_team Player Team * $on_team Enemy Team’ * $attack W Att * health Enemy H * opp Team Team’ * nat_minus H Att H’ -o health Enemy H’.
119. 119 attack : turn Player * $attack W Att * health Enemy H -o subtract Enemy H Att. Attacking
120. 120 subtract/s : subtract P (s Health) (s Att) -o subtract P Health Att. ! subtract/done : subtract P H z -o health P H. ! subtract/die : subtract P z Att -o dead P. Forward-Chaining Subtraction
121. 121 nat_minus nat nat nat : bwd. minus/z- : nat_minus z N z. minus/-z : nat_minus N z N. minus/s : nat_minus (s N) (s M) P <- nat_minus N M P. Backward-Chaining Subtraction
122. opp team team : bwd. opp blue yellow. opp yellow blue. 122 Persistent Predicates
123. 123 Types and Predicates team : type. blue : team. yellow : team. ! player : type. ! on_team player team : pred. health player nat : pred. attack player nat : pred.
124. 124 Types and Predicates nat : type. z : nat. s nat : nat. (Operators on numbers can be defined in the language via backward chaining, or by accessing built-in functions.)
125. 125
126. 126 PROBLEM 2: Feature Creep
127. 127 Interactive Fiction (IF)
128. 128 Interactive Fiction (IF)
129. 129 Twine Graph + hidden state
130. 130 Forward Chaining
131. 131 A formal language for describing stories and games makes it easier to sketch and invent novel designs. Thesis Statement (Take 1)
132. 132 Thesis Statement (Take 1) A formal language for describing stories and games makes it easier to sketch and invent novel designs.