Description
Your!assignment!is!to!build!a!knowledge3based!agent!who!can!solve!problems!in!the! Wumpus!World.! ! You!will!have!access!to!code!that!builds!and!manages!a!world!for!you.!!It!will!take! actions!as!input!and!return!the!state!of!the!world!that!results!from!those!actions.!! ! In!general,!you!can!take!actions!that!change!the!direction!you!are!facing,!move! forward!and!either!pick!things!up!or!shoot!an!arrow.!Once!you!have!scored!some! points!and!returned!to!your!home,!you!can!also!leave!the!game.! ! Moves&that&change&your&orientation:&&Up,!Down,!Left,!Right& ! The&move&that&changes&your&position:&Step& ! The&move&that&allows&you&to&exit&the&board:&Exit& ! Actions&that&change&the&world&aside&from&your&position:&PickUp,&Shoot& ! You!invoke!these!actions!by!calling!the!function!take_action!(in!the!file! updatewumpus.py)!that!takes!the!name!of!a!world!(more!on!that!shortly)!and!a! move.!!It!returns!a!list!of!strings!that!describes!the!current!perceptions!that!are! available!to!you:! ! ! (smell,!air,!glitter,!bump,!scream,!location,!orientation,!status,!score)! ! The!possible!values!of!these!perceptions!are:! ! Smell!3!clean|nasty! Air!3!calm|breeze! Glitter!3!bare|glitter! Bump!3!no_bump|bump! Scream!3!quiet|scream! Location!3!unique!identifier!for!current!square! Orientation!3!the!direction!you!are!facing! Status!3!living|dead|won! Score!3!current!score!! Before!you!start!the!game,!you!need!to!initialize!a!“world.”!!You!do!this!by!calling! intialize_world,!a!function!that!has!no!arguments.!!This!returns!the!name!of!a!new! world!that!you!need!to!use!when!calling!take_action.!!This!function!builds!a!folder!! (“WumpusWorldDataFolder!“)!where!the!world!data!will!be!saved.!!It!does!not!
delete!any!of!the!worlds!it!builds!(but!they!are!tiny)!so!you!might!want!to!clear!this! folder!occasionally.!!It!didn’t!want!to!include!any!code!that!removes!files/folders.! ! You!will!need!to!download!updatewumpus.py!and!include!it!in!your!agent!file:! ! ! include!updatewumpus! ! You!will!need!to!initialize!a!world!before!you!start!to!play!and!hold!onto!the!name!of! that!world:! ! ! world_name!=!updatewumpus.intialize_world()! ! At!run!time,!you!will!get!a!message!like!this:! ! Initializing!your!new!Wumpus!world!! Your!new!world!is!called:!Wumpus3231! You!are!starting!in!Cell!11,!looking!to!the!Right.! You!are!starting!with!0!points,!1!arrow(s).! You!are!alive.!! Now!you!can!take!actions!by!!calling!take_action:! ! ! updatewumpus.take_action(name,!”Up”)! ! or!! ! ! updatewumpus.take_action(name,!”Step”)! ! take_action!will!return!a!precept!list!every!time!it!is!called!that!looks!like!this:! ! ! [‘clean’,!’calm’,!’bare’,!’no_bump’,!’quiet’,!’Cell!11′,!’Up’,!’living’,!0]! ! or! ! ! [‘nasty’,!’calm’,!’bare’,!’no_bump’,!’quiet’,!’Cell!12′,!’Up’,!’living’,!0]! ! It!will!also!provide!you!with!messaging!so!you!can!track!the!game:! ! *********************************! ! Turing!to!face!Up! Perception!=!(clean,!calm,!bare,!no_bump,!quiet,!Cell!11,!Up,!living,!0)! ! *********************************! ! Taking!a!step!
Moving!to!Cell!12! There!is!a!nasty!smell!in!here! Perception!=!(nasty,!calm,!bare,!no_bump,!quiet,!Cell!12,!Up,!living,!0)!! You!can!also!get!the!names!of!adjacent!cells!by!calling!look_ahead.!It!takes!the!name! of!the!world!and!returns!a!list!of!the!cells!that!are!next!to!you.! ! ! updatewumpus.lookahead(world_name)! ! returns! ! ! [‘Cell!13′,!’Cell!11′,!‘Cell!22’]! ! The!idea!behind!this!is!you!can!use!this!information!start!to!ASSERT!facts!about!the! world!as!you!play.!! ! Once!you!die,!the!world!will!no!long!update!and!your!status!will!change!to!“dead”!in! you!perception!list.!Also:! ! You!cannot!PickUp!the!gold!if!there!is!no!gold.! You!only!have!one!arrow!to!Shoot.! You!can!only!Exit!if!you!have!scored!some!points!and!are!at!your!home.! Once!you!have!killed!the!Wumpus,!you!can!enter!its!room!without!dying.!! The&assignment.& ! You!goal!is!to!build!an!agent!that!is!able!to!move!safely!through!its!world,!collect! gold,!kill!the!Wumpus,!and!then!exit.! ! Given!that!you!are!starting!with!no!knowledge!of!the!world,!you!are!going!to!have!to! have!your!agent!figure!things!out!as!it!goes!along.!!You!will!need!to!build!up!a!set!of! inference!rules!that!will!fire!as!new!facts!are!known.! ! For!example,!if!you!are!on!a!square!with!no!breeze,!then!you!can!add!this!fact!to!the! data,!add!facts!about!what!squares!are!adjacent!to!it,!and!then!infer!that!those! squares!have!solid!floors.! ! That!is,!ASSERT:! ! Calm(Cell!11)! Adjacent(Cell!11,!Cell!12)! Adjacent((Cell!11,!Cell!21)!! And!then!use!a!rule!like:! ! Calm(?x)!V!Adjacent(?x!?y)!=!Solid(?y)!
! to!make!the!right!inferences.! ! You!will!need!to!use!your!knowledge!base!to!figure!out!which!squares!have!solid! floors!and!no!Wumpus,!are!safe!(solid!floor!and!no!Wumpus),!and!where!the! Wumpus!is!so!you!can!shoot!it.!!AS!you!wander,!you!should!probably!also!be! thinking!about!how!to!save!information!about!what!constitutes!as!good!path!back!to! the!start.! ! The!approach!we!are!taking!is!to!use!a!knowledge!base!as!the!repository!of!what!is! true!(i.e.,!known!by!the!system)!and!another!system!(a!planner)!to!make!decisions! based!on!what!it!knows!and!what!it!wants!to!accomplish.! ! The!knowledge!side!of!things!requires!a!repository!of!facts!and!a!repository!of!rules.!! As!we!discussed,!as!new!rules!are!added,!we!check!to!see!if!they!allow!you!to!infer! anything!given!the!fact!that!you!know.!!Likewise,!as!you!add!new!facts,!you!need!to! check!to!see!if!any!rules!can!be!fired.! ! In!order!to!access!this!information!you!will!need!to!be!able!to:!! ! & ASSERT!facts!and!rules.!(This!room!has!no!breeze.)! & ASK!if!things!you!care!about!are!true?!(Is!this!room!I!want!to!go!into!Safe?)! ! Your!agent!should!have!specific!goals!it!is!trying!to!accomplish!(pick!up!the!gold)! and!know!that!it!will!have!to!take!actions!in!order!to!set!up!the!conditions!that! makes!this!possible!(stand!in!the!same!room!as!the!gold).! ! The!challenge!is!that!you!will!need!to!be!able!to!not!just!add!facts!but!also!draw! inferences!from!them.!!Your!inference!rules!will!need!to!have!variables!so!that!they! are!general.!!You!will!need!to!be!able!to!MATCH!facts!against!patterns!in!your! inference!rules.!And!when!you!draw!an!inference,!you!will!need!to!INSTANTIATE! the!result!and!thus!create!a!new!fact!with!all!of!the!variables!replaced!with!the! elements!from!the!fact!that!was!matched!against!it.! ! And!you!will!need!to!be!able!to!do!the!same!sort!of!matching!for!ASK&so!you!can!look! for!the!answers!to!general!queries.! ! There!is!a!very!simple!implementation!of!MATCH!and!INSTANTIATE!in!the!file! FOPC.py.!!! ! On!Tuesday,!we!will!discuss!this!in!class!and!you!will!get!the!second!piece!of!this! assignment!that!will!be!a!somewhat!expanded!Wumpus!world!in!which!you!will! need!to!kill!the!Wumpus!in!order!to!get!to!your!goal.! ! & &
Deliverables& ! You!will!be!handing!in!y