CLP(Z) - top-level first time failure about trealla HOT 2 CLOSED

?- ~/trealla (devel) $ tpl ~/scryer-prolog/src/lib/clpz.pl
?- [user]. :-dynamic(f/1). f(X) :- X #> 3, X #< 20.
   true.
?- listing(f/1).
f(A) :- (integer(A)->A>=3+1;B=4,clpz:clpz_geq(A,B)),(integer(A)->20>=A+1;C=20,clpz:clpz_geq(C,A+1)).
   true.
?- f(X).
   clpz:(X in 4..19).
?- clause(f(X),B), assertz((g(X) :- B)).
   B = ((integer(X)->X>=3+1;_A=4,clpz:clpz_geq(X,_A)),(integer(X)->20>=X+1;_B=20,clpz:clpz_geq(_B,X+1))).
?- g(X).
   clpz:(X in 4..19).