Theorem 3eqtr4rd 2083

Description: A deduction from three chained equalities. (Contributed by NM, 21-Sep-1995.)

Hypotheses

Ref	Expression
3eqtr4d.1	|- ( ph -> A = B )
3eqtr4d.2	|- ( ph -> C = A )
3eqtr4d.3	|- ( ph -> D = B )

Assertion

Ref	Expression
3eqtr4rd	|- ( ph -> D = C )

Proof of Theorem 3eqtr4rd

Step	Hyp	Ref	Expression
1		3eqtr4d.3	. . 3 |- ( ph -> D = B )
2		3eqtr4d.1	. . 3 |- ( ph -> A = B )
3	1, 2	eqtr4d 2075	. 2 |- ( ph -> D = A )
4		3eqtr4d.2	. 2 |- ( ph -> C = A )
5	3, 4	eqtr4d 2075	1 |- ( ph -> D = C )

Syntax hints:   -> wi 4   = wceq 1243

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-5 1336  ax-gen 1338  ax-4 1400  ax-17 1419  ax-ext 2022

This theorem depends on definitions:  df-bi 110  df-cleq 2033

This theorem is referenced by:  csbcnvg  4519  phplem4  6318  phplem4on  6329  recexnq  6488  prarloclemcalc  6600  addcomprg  6676  mulcomprg  6678  mulcmpblnrlemg  6825  axmulass  6947  divnegap  7683  modqlt  9175  modqmulnn  9184  iseqcaopr3  9240  cjreb  9466  recj  9467  imcj  9475  imval2  9494  resqrexlemover  9608  sqrtmul  9633  amgm2  9714