Theorem a1dd 48

Description: Deduction introducing a nested embedded antecedent. (Contributed by NM, 17-Dec-2004.) (Proof shortened by O'Cat, 15-Jan-2008.)

Hypothesis

Ref	Expression
a1dd.1	|- ( ph -> ( ps -> ch ) )

Assertion

Ref	Expression
a1dd	|- ( ph -> ( ps -> ( th -> ch ) ) )

Proof of Theorem a1dd

Step	Hyp	Ref	Expression
1		a1dd.1	. 2 |- ( ph -> ( ps -> ch ) )
2		ax-1 6	. 2 |- ( ch -> ( th -> ch ) )
3	1, 2	syl6 33	1 |- ( ph -> ( ps -> ( th -> ch ) ) )

This proof depends on syntax axioms:   -> wi 4

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7

This theorem is used by:  exmidsssnc  4340  nnsub  9345  difelfzle  10551  facdiv  11190  facwordi  11192  faclbnd  11193  pfxccat3  11520  dvdsabseq  12630  divgcdcoprm0  12895  exprmfct  12933  prmfac1  12947  pockthg  13156  clwwlknonex2lem2  16777  bj-inf2vnlem2  17095