1		:- multifile generate/2.
2		:- multifile shrink/3.
3
4		% any expression
5		generate(prob_ast_expr(Option),Value) :-
6		random_member(Type,[prob_ast_set_expr(Option),prob_ast_int_expr(Option),prob_ast_seq_expr(Option)]),
7		generate(Type,Value).
8
9		% differenciate between record, integer, set or sequence expression
10		shrink(Type,Value,Shrunken) :-
11		Type =.. [prob_ast_expr|_] ,
12		Value = b(_,record(_),_) ,
13		shrink(prob_ast_record,Value,Shrunken).
14
15		shrink(Type,Value,Shrunken) :-
16		Type =.. [prob_ast_expr|_] ,
17		Value = b(_,set(_),_) ,
18		shrink(prob_ast_set_expr,Value,Shrunken).
19
20		shrink(Type,Value,Shrunken) :-
21		Type =.. [prob_ast_expr|_] ,
22		Value = b(_,seq(_),_) ,
23		shrink(prob_ast_seq_expr,Value,Shrunken).
24
25		shrink(Type,Value,Shrunken) :-
26		Type =.. [prob_ast_expr|_] ,
27		Value = b(_,integer,_) ,
28		shrink(prob_ast_int_expr,Value,Shrunken).