/* This is a truely silly program, since it is based on my own
medical knowledge. 
Ask: ?-itch.    or ?-lesion.    or ?-help. to get it started. */


help :- print( 'Diagnose the following topics:' ), nl, 
print( 'Itch.' ), nl, print( 'lesion' ).


itch :- print( 'Is the atmosphere dry?: ' ), 'say yes',
  print( 'Do not take so many showers. Use vaseline.' ).

itch :- print( 'Does the patient have an allergic history?: '), 
  'say yes', not(fever),  print( 'Consider atopic dermatitis.' ).

fever  :- 
  print( 'Does the patient have a fever?' ), 'say yes'.

'non infective' :- acne, 'severe acne'.
'non infective' :- acne, 'cystic acne'.
'non infective' :- acne.
'non infective' :- 'severe acne rosacea'.
'non infective' :- 'rosacea'.

lesion :- not( fever ), 'non infective'.


acne :- 
  print( 'Is the skin oily?' ), 'say yes',
  print( 'Are there lots of pimples?' ), 'say yes',
  print( 'Condition is probably acne.' ). 

'cystic acne' :- 
  print( 'Are there many yellowish cysts?' ), 'say yes', 
  print( 'Condition is cystic acne.' ).

'severe acne' :- 
  print( 
    'Are there large elevated bluish abscesses with disfiguring scars?' ), 
  'say yes'.

'rosacea' :- print( 'Is the patient  a woman?' ), 'say yes', 
             'acne rosacea'.


'acne rosacea' :-  'severe'.
'acne rosacea' :-  'mild'.

'severe' :- 
  print( 'Does the patient have an enlarged nose, with growths?' ), 'say yes',
  print( 'Diagnosis is severe acne rosacea.' ).

'mild' :- 
  print( 'Is the skin oily, with a tendency towards seborrhea?' ), 'say yes',
  print( 'Are there pustules surrounded by a reddish area?' ), 'say yes',
  print( 'But are they larger than ordinary acne eruptions?' ), 'say yes',
  print( 'Diagnosis is acne rosacea.' ).


'say yes' :- read( Ans ), yes( Ans ), nl.


yes( yes ).
yes( y ).
yes( yea ).
yes( yup ).