Approved BLD Demonstrate equational use of equality Define a predicate to be true when x^3-x=0 Equality_in_condition-premise.rif http://www.w3.org/2005/rules/test/repository/tc/Equality_in_condition/Equality_in_condition-premise.rif ) Prefix(func ) Prefix(pred ) Prefix(xs ) Group( Forall ?x ( ex:root(?x) :- And (External(pred:is-literal-decimal(?x)) External(func:numeric-subtract(External(func:numeric-multiply(?x External(func:numeric-multiply(?x ?x)))) ?x)) = "0"^^xs:decimal ) ) ) ) ]]> Equality_in_condition-conclusion.rif http://www.w3.org/2005/rules/test/repository/tc/Equality_in_condition/Equality_in_condition-conclusion.rif