Metamath Proof Explorer


Theorem sbtT

Description: A substitution into a theorem remains true. sbt with the existence of no virtual hypotheses for the hypothesis expressed as the empty virtual hypothesis collection. (Contributed by Alan Sare, 4-Feb-2017) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypothesis sbtT.1 ⊢ ⊤ → φ
Assertion sbtT ⊢ y x φ

Proof

Step Hyp Ref Expression
1 sbtT.1 ⊢ ⊤ → φ
2 1 mptru ⊢ φ
3 2 sbt ⊢ y x φ