wff

Etymology

noun

1. Acronym of well-formed formula.
   which are of the form P(S) and hence we know that we can decide its truth value if we can decide the truth Value of all d-wff's of form P(S). But if it is of the form P(S ) then it is equivalent to P(T) where T is the dans of S. But by the principle of […] 1964, On the Occurrence of Non-deontic WFF's in Argument Forms Having Deontic WFF's as Conclusion
   A grammatically correct expression is called a well-formed formula, or wff for short, which can be pronounced "woof." To decide whether an expression is a wff , we need to precisely define the syntax (or grammar) rules for the formation of wffs […] 2001, James L. Hein, Discrete Structures, Logic, and Computability, Jones & Bartlett Learning, page 350
   The set of well-formed formulas (wffs) is the smallest set satisfying the following conditions: • If p is an n-ary predicate symbol (an element of Pn) and t1 ,. .., tn are terms, p(t1 ,. ..,tn) is a wff. • If p is a wff and x is a variable, (∀x)p and (∃x)p are […] 2002, Fernando C. N. Pereira, Stuart M. Shieber, Prolog and Natural-Language Analysis, Microtome Publishing, page 76