an extension point for specializations of the equivalence tag name.
An equivalence expression, which is "syntactic sugar" for a pair of conjoined converse implication rules (<Implies>).
It consists of a pair of (optionally skipped) <torso> roles.
For example, "A person owning an object is equivalent to an object belonging to a person":
See http://deliberation.ruleml.org/1.02/glossary/#gloss-Equivalent
<Equivalent>: Syntactic sugar for two implications. See
http://deliberation.ruleml.org/1.02/glossary/#gloss-Equivalent
the main content model of equivalances consists of two "torso" formulas
an extension point for stripe skipping as well as specializations of the torso tag name in equivalences.
A symmetric role used in an equivalence expression (<Equivalent>) combining the asymmetric <then> and <if>.
<torso>: contains one formula within an equivalence. See
http://deliberation.ruleml.org/1.02/glossary/#gloss-torso
An equivalance is syntactic sugar for two implications.
In all RuleML languages, formulas allowed as premises are the same or more general than those allowed as conclusions,
because this is a requirement for the statement "P implies P" to be syntactically valid whenever P is a valid conclusion.
Therefore, formulas allowed in equivalences are the same as those allowed in conclusions.