/* 

  Alarm in Picat.

  https://homepages.ecs.vuw.ac.nz/~yimei/resources/COMP307/lec16_Tutorial_GoodExample_BuildingBN.pdf
  """
  Situation:
  - I'm at work
  - John calls to say that the in my house alarm went off
    but Mary (my neighbor) did not call
  - The alarm will usually be set off by burglars
    but sometimes it may also go off because of minor earthquakes
  Variables:
    Burglary, Earthquake, Alarm, JohnCalls, MaryCalls
  Network topology reflects causal knowledge:
  - A burglar can set the alarm off
  - An earthquake can set the alarm off
  - The alarm can cause Mary to call
  - The alarm can cause John to cal
  """


  This program was created by Hakan Kjellerstrand, hakank@gmail.com
  See also my Picat page: http://www.hakank.org/picat/

*/

import ppl_distributions,ppl_utils.

main => go.

/*
  This model

  var : burglary
  Probabilities:
  true: 0.7867760123013839
  false: 0.2132239876986161
  mean = [true = 0.786776,false = 0.213224]

  var : earthquake
  Probabilities:
  false: 0.7721681189133778
  true: 0.2278318810866223
  mean = [false = 0.772168,true = 0.227832]

  var : alarm
  Probabilities:
  true: 0.7139928241927217
  false: 0.2860071758072783
  mean = [true = 0.713993,false = 0.286007]

  var : calls(john)
  Probabilities:
  true: 1.0000000000000000
  mean = [true = 1.0]

  var : calls(mary)
  Probabilities:
  false: 1.0000000000000000
  mean = [false = 1.0]


*/
go ?=>
  reset_store,
  run_model(10_000,$model,[show_probs,mean]),
  fail,  
  nl.
go => true.
  

calls(X,Alarm) = cond(Alarm, flip(0.8),flip(0.1)).

model() =>
  Burglary   = flip(0.7),
  Earthquake = flip(0.2),
  Alarm      = cond( (Burglary, Earthquake), flip(0.9),
                      cond( (Burglary, not Earthquake), flip(0.8),
                           cond( (not Burglary, Earthquake), flip(0.1),
                                false))),
  CallsJohn  = calls(john,Alarm),
  CallsMary  = calls(mary,Alarm),
  
  observe(CallsJohn, not CallsMary),

  if observed_ok  then
    add("burglary",Burglary),
    add("earthquake",Earthquake),        
    add("alarm",Alarm),
    add("calls(john)",CallsJohn),
    add("calls(mary)",CallsMary),
  end.




go2 ?=>
  reset_store,
  run_model(10_000,$model2,[show_probs,mean]),
  fail,  
  nl.
go2 => true.
  

calls(X,Alarm) = cond(Alarm, flip(0.8),flip(0.1)).

model() =>
  Burglary   = flip(0.7),
  Earthquake = flip(0.2),
  Alarm      = cond( (Burglary, Earthquake), flip(0.9),
                      cond( (Burglary, not Earthquake), flip(0.8),
                           cond( (not Burglary, Earthquake), flip(0.1),
                                false))),
                                
  CallsJohn  = calls(john,Alarm),
  CallsMary  = calls(mary,Alarm),
  
  observe(CallsJohn, not CallsMary),

  if observed_ok  then
    add("burglary",Burglary),
    add("earthquake",Earthquake),        
    add("alarm",Alarm),
    add("calls(john)",CallsJohn),
    add("calls(mary)",CallsMary),
  end.