Some many-valued logics may have incompatible definitions of equivalence and order (entailment). The entailment relation in full CLL is undecidable. The dualist's challenge is to explain supervenience without entailment. The possibility of "supervenience without entailment" or "supervenience without reduction" is contested territory among philosophers. In pragmatics, entailment falls in a category with implicature and presupposition. In this respect, presupposition is distinguished from entailment and implicature. The RDFS entailment is a standard entailment relation in the semantic web. Checking entailment of a constraint is done via guards to clauses. Textual entailment is similar but weakens the relationship to be unidirectional. Entailment also does not allow for a lack of referent. They are degrees of (partial) entailment, or degrees of logical consequence, not degrees of belief. That entailment clearly reflects the operation of agnatic primogeniture, also known as the Salic law. Muggleton implemented Inverse entailment first in the PROGOL system. Ladusaw (1980) proposed that downward entailment is the property that licenses polarity items. Revonsuo equates this to "consciousness-related binding", emphasizing the entailment of a phenomenal aspect.