Theorem eqtr2id 2211

Description: An equality transitivity deduction. (Contributed by NM, 29-Mar-1998.)

Hypotheses

Ref	Expression
eqtr2id.1	|- A = B
eqtr2id.2	|- ( ph -> B = C )

Assertion

Ref	Expression
eqtr2id	|- ( ph -> C = A )

Proof of Theorem eqtr2id

Step	Hyp	Ref	Expression
1		eqtr2id.1	. . 3 |- A = B
2		eqtr2id.2	. . 3 |- ( ph -> B = C )
3	1, 2	syl5eq 2210	. 2 |- ( ph -> A = C )
4	3	eqcomd 2171	1 |- ( ph -> C = A )

Syntax hints:   -> wi 4   = wceq 1343

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-5 1435  ax-gen 1437  ax-4 1498  ax-17 1514  ax-ext 2147

This theorem depends on definitions:  df-bi 116  df-cleq 2158

This theorem is referenced by:  eqtr3di  2213  opeqsn  4229  dcextest  4557  relop  4753  funopg  5221  funcnvres  5260  mapsnconst  6656  snexxph  6911  apreap  8481  recextlem1  8544  nn0supp  9162  intqfrac2  10250  hashprg  10717  hashfacen  10745  explecnv  11442  rerestcntop  13150  binom4  13497