Theorem 3imtr3i 199

Description: A mixed syllogism inference, useful for removing a definition from both sides of an implication. (Contributed by NM, 10-Aug-1994.)

Hypotheses

Ref	Expression
3imtr3.1	|- ( ph -> ps )
3imtr3.2	|- ( ph <-> ch )
3imtr3.3	|- ( ps <-> th )

Assertion

Ref	Expression
3imtr3i	|- ( ch -> th )

Proof of Theorem 3imtr3i

Step	Hyp	Ref	Expression
1		3imtr3.2	. . 3 |- ( ph <-> ch )
2		3imtr3.1	. . 3 |- ( ph -> ps )
3	1, 2	sylbir 134	. 2 |- ( ch -> ps )
4		3imtr3.3	. 2 |- ( ps <-> th )
5	3, 4	sylib 121	1 |- ( ch -> th )

Syntax hints:   -> wi 4   <-> wb 104

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107

This theorem depends on definitions:  df-bi 116

This theorem is referenced by:  cbv1  1733  cbv1v  1735  moimv  2080  hblem  2274  tfi  4559  smores  6260  idssen  6743  suplocsrlem  7749  bezoutlemle  11941  limcmpted  13272  sincosq3sgn  13389  subctctexmid  13881  dcapnconstALT  13940