Theorem 3eqtr2d 2078

Description: A deduction from three chained equalities. (Contributed by NM, 4-Aug-2006.)

Hypotheses

Ref	Expression
3eqtr2d.1	⊢ (𝜑 → 𝐴 = 𝐵)
3eqtr2d.2	⊢ (𝜑 → 𝐶 = 𝐵)
3eqtr2d.3	⊢ (𝜑 → 𝐶 = 𝐷)

Assertion

Ref	Expression
3eqtr2d	⊢ (𝜑 → 𝐴 = 𝐷)

Proof of Theorem 3eqtr2d

Step	Hyp	Ref	Expression
1		3eqtr2d.1	. . 3 ⊢ (𝜑 → 𝐴 = 𝐵)
2		3eqtr2d.2	. . 3 ⊢ (𝜑 → 𝐶 = 𝐵)
3	1, 2	eqtr4d 2075	. 2 ⊢ (𝜑 → 𝐴 = 𝐶)
4		3eqtr2d.3	. 2 ⊢ (𝜑 → 𝐶 = 𝐷)
5	3, 4	eqtrd 2072	1 ⊢ (𝜑 → 𝐴 = 𝐷)

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:  fmptapd  5354  rdgisucinc  5972  mulidnq  6487  ltrnqg  6518  recexprlem1ssl  6731  recexprlem1ssu  6732  ltmprr  6740  mulcmpblnrlemg  6825  caucvgsrlemoffcau  6882  negsub  7259  neg2sub  7271  divmuleqap  7693  divneg2ap  7712  qapne  8574  binom2  9362  crim  9458  remullem  9471