Description: Change bound variable. Uses only Tarski's FOL axiom schemes. Part of Lemma 7 of KalishMontague p. 86. (Contributed by Wolf Lammen, 5-Mar-2023)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | wl-motae | |- ( E* u T. -> A. x y = z ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | wl-cbvmotv | |- ( E* u T. -> E* v T. ) |
|
| 2 | wl-moteq | |- ( E* v T. -> y = z ) |
|
| 3 | 2 | alrimiv | |- ( E* v T. -> A. x y = z ) |
| 4 | 1 3 | syl | |- ( E* u T. -> A. x y = z ) |