Metamath Proof Explorer


Theorem frins2f

Description: Founded Induction schema, using implicit substitution. (Contributed by Scott Fenton, 6-Feb-2011) (Revised by Mario Carneiro, 11-Dec-2016)

Ref Expression
Hypotheses frins2f.1
|- R Fr A
frins2f.2
|- R Se A
frins2f.3
|- F/ y ps
frins2f.4
|- ( y = z -> ( ph <-> ps ) )
frins2f.5
|- ( y e. A -> ( A. z e. Pred ( R , A , y ) ps -> ph ) )
Assertion frins2f
|- ( y e. A -> ph )

Proof

Step Hyp Ref Expression
1 frins2f.1
 |-  R Fr A
2 frins2f.2
 |-  R Se A
3 frins2f.3
 |-  F/ y ps
4 frins2f.4
 |-  ( y = z -> ( ph <-> ps ) )
5 frins2f.5
 |-  ( y e. A -> ( A. z e. Pred ( R , A , y ) ps -> ph ) )
6 5 3 4 frins2fg
 |-  ( ( R Fr A /\ R Se A ) -> A. y e. A ph )
7 1 2 6 mp2an
 |-  A. y e. A ph
8 7 rspec
 |-  ( y e. A -> ph )