Theorem eqsstrrdi 3281

Description: A chained subclass and equality deduction. (Contributed by Mario Carneiro, 2-Jan-2017.)

Hypotheses

Ref	Expression
eqsstrrdi.1	⊢ (𝜑 → 𝐵 = 𝐴)
eqsstrrdi.2	⊢ 𝐵 ⊆ 𝐶

Assertion

Ref	Expression
eqsstrrdi	⊢ (𝜑 → 𝐴 ⊆ 𝐶)

Proof of Theorem eqsstrrdi

Step	Hyp	Ref	Expression
1		eqsstrrdi.1	. . 3 ⊢ (𝜑 → 𝐵 = 𝐴)
2	1	eqcomd 2237	. 2 ⊢ (𝜑 → 𝐴 = 𝐵)
3		eqsstrrdi.2	. 2 ⊢ 𝐵 ⊆ 𝐶
4	2, 3	eqsstrdi 3280	1 ⊢ (𝜑 → 𝐴 ⊆ 𝐶)

Syntax hints:   → wi 4   = wceq 1398   ⊆ wss 3201

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-11 1555  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-ext 2213

This theorem depends on definitions:  df-bi 117  df-nf 1510  df-sb 1811  df-clab 2218  df-cleq 2224  df-clel 2227  df-in 3207  df-ss 3214

This theorem is referenced by:  ffvresb  5818  tposss  6455  sbthlemi5  7203  iooval2  10194  telfsumo  12090  structcnvcnv  13161  ressbasssd  13215  txss12  15060  txbasval  15061