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
|- ( T. -> ph )
Assertion sbtT
|- [ y / x ] ph

Proof

Step Hyp Ref Expression
1 sbtT.1
 |-  ( T. -> ph )
2 1 mptru
 |-  ph
3 2 sbt
 |-  [ y / x ] ph