|General validity: within a calculus a formula that is satisfied by any interpretation (variable assignment with expressions for objects) is valid. See also satisfaction, satisfiability, interpretation.|
Books on Amazon:
|EMD II 201f
structurally valid / Davidson: inferences which involve only truth theory plus translation rules without truth conditions?
II 204 inference-patterns are the same for object language and meta language -
s.v. A: if truth is defined directly: for each set S and S*, S and S* is true if and only if S is true and S* is true. -
B: if truth is not defined directly: if F (S) is a sentence in the fragment that is mapped to S, through the translation rules, then S1, ... Sn-1 formally include Sn, if and only if F (S 1), ... F (n-1 formally include F (Sn) .
G. Evans/J. McDowell
Truth and Meaning Oxford 1977
The Varieties of Reference (Clarendon Paperbacks) Oxford 1989