<HTML> <HEAD>  <TITLE>The Mercury Language Reference Manual - Footnotes</TITLE> </HEAD> <BODY> <H1>The Mercury Language Reference Manual</H1> <H3><A NAME="FOOT1" HREF="reference_manual.html#FOOT1">(1)</A></H3> Operator term (see section <A HREF="reference_manual.html#SEC5">Terms</A>). <H3><A NAME="FOOT2" HREF="reference_manual.html#FOOT2">(2)</A></H3> The type of an explicitly type qualified term may be an instance of the type specified by the qualifier. This allows explicit type qualifications to constrain the types of two data-terms to be identical, without knowing the exact types of the data-terms. It also allows type qualifications to refer to the types of the results of existentially typed predicates or functions. <H3><A NAME="FOOT3" HREF="reference_manual.html#FOOT3">(3)</A></H3> If <VAR>equalitypred</VAR> is not an equivalence relation, then the program is inconsistent: its declarative semantics contains a contradiction, because the additional axioms for the user-defined equality contradict the standard equality axioms. That implies that the implementation may compute any answer at all (see section <A HREF="reference_manual.html#SEC83">Semantics</A>), i.e. the behaviour of the program is undefined. </BODY> </HTML>