Returns the result of showExpr in a List.
Returns the result of showExpr in a List. Can be overridden
to accumulate the string representations of sub-predicates.
Checks if t satisfies the predicate P.
Checks if t does not satisfy the predicate P.
Type class for validating values of type
Taccording to a type-level predicateP. The semantics ofPare defined by the instance(s) of this type class forP.