has All Variables
Determines whether the declaration has all variables that satisfy the provided predicate.
Note that if the variables contains no elements, the variable returns true
because there are no elements in it that do not match the predicate. See a more detailed explanation of this logic concept in "Vacuous truth" article.
Return
true
if all variable declarations satisfy the predicate, false
otherwise.
Parameters
predicate
A variable that defines the condition to be met by variable declarations.