:- import get_call/2, table_state/2, get_returns/2 from tables.
:- import abolish_table_info/0 from machine.
 
test :- abolish_table_info, int(p(X,Y)),writeln([X,Y]),fail. 
 
% interpreter 
 
:- thread_shared int/1.
:- table int/1. 
 
int(G) :- rule(G,B),int_c(B).

int_c(G) :- 
        G == true   
         ->     true 
         ; G = (A,B) 
         ->     int_c(A),int_c(B)
         ; in_table(int(G),C,R)     % if completed table for this call 
         ->     get_returns(C,R)
         ;      int(G)
        .

in_table(Call,C,R) :-
	get_call(Call,C,R), table_state(Call,complete).

rule(p(X,Y),a(X,Y)).
rule(p(X,Y),(p(X,Z),p(Z,Y))).
rule(a(1,2),true).
rule(a(2,3),true).
rule(a(3,1),true).