Metamath Proof Explorer


Theorem msubval

Description: A substitution applied to an expression. (Contributed by Mario Carneiro, 18-Jul-2016)

Ref Expression
Hypotheses msubffval.v V=mVRT
msubffval.r R=mRExT
msubffval.s S=mSubstT
msubffval.e E=mExT
msubffval.o O=mRSubstT
Assertion msubval F:ARAVXESFX=1stXOF2ndX

Proof

Step Hyp Ref Expression
1 msubffval.v V=mVRT
2 msubffval.r R=mRExT
3 msubffval.s S=mSubstT
4 msubffval.e E=mExT
5 msubffval.o O=mRSubstT
6 1 2 3 4 5 msubfval F:ARAVSF=eE1steOF2nde
7 6 3adant3 F:ARAVXESF=eE1steOF2nde
8 simpr F:ARAVXEe=Xe=X
9 8 fveq2d F:ARAVXEe=X1ste=1stX
10 8 fveq2d F:ARAVXEe=X2nde=2ndX
11 10 fveq2d F:ARAVXEe=XOF2nde=OF2ndX
12 9 11 opeq12d F:ARAVXEe=X1steOF2nde=1stXOF2ndX
13 simp3 F:ARAVXEXE
14 opex 1stXOF2ndXV
15 14 a1i F:ARAVXE1stXOF2ndXV
16 7 12 13 15 fvmptd F:ARAVXESFX=1stXOF2ndX