Description: A weak form of specialization. Lemma 8 of KalishMontague p. 87. Uses only Tarski's FOL axiom schemes. For stronger forms using more axioms, see spimv and spimfv . (Contributed by NM, 9-Apr-2017)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | spimvw.1 | |- ( x = y -> ( ph -> ps ) ) |
|
| Assertion | spimvw | |- ( A. x ph -> ps ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | spimvw.1 | |- ( x = y -> ( ph -> ps ) ) |
|
| 2 | ax-5 | |- ( -. ps -> A. x -. ps ) |
|
| 3 | 2 1 | spimw | |- ( A. x ph -> ps ) |