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Download Ciao Manual - The Ciao System
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586 The Ciao System Declares determinacy conditions for a predicate. Conditions Cond are on variables of arguments of Pred. For example, in: :- determinate(member(A,B,C), ( A ?= term(B,[1]) ; C?=[_|_]) ). member(A,[A|B],B). member(A,[B|C],[B|D]) :A==B, member(A,C,D). the declaration states that a call member(A,B,C) is determinate when either A doesn’t unify with the first argument of B or C doesn’t unify with [_|_]. Usage: :- determinate(Pred,Cond). States that the predicate Pred is determinate when Cond holds. − The following properties should hold at call time: Pred is a Name/Arity structure denoting a predicate name: predname(P/A) :atm(P), nnegint(A). (basic props:predname/1) Cond is a determinacy condition. (user(/home/ciaobot/ciaobotdata/pm ubuntu/source/master/CiaoDE/ciao/library/andorra/andorra doc):detcond/1) 112.3 Documentation on exports (andorra_doc) detcond/1: REGTYPE Defined by: detcond(ground(X)) :var(X). detcond(nonvar(X)) :var(X). detcond(instatiated(A,Path)) :var(A), list(Path,int). detcond(?\=(Term1,Term2)) :path(Term1), path(Term2). detcond(?=(Term1,Term2)) :path(Term1), path(Term2). detcond(Test) :( test Test ). • ground/1 and nonvar/1 have the usual meaning. • instatiated(A,Path) means that the subterm of A addressed by Path is not a variable. Path is a list of integer numbers describing a path to the subterm regarding the whole term A as a tree. For example, instantiated(f(g(X),h(i(Z),Y)),[2,1]) tests whether i(Z) is not a variable. • Term1 ?\= Term2 means “terms Term1 and Term2 do not unify (when instantiated)”. Term1 and Term2 can be either an argument of the predicate or a term term(V,Path), which refers to the subterm of V addressed by Path.
