Theorem eqsstrrdi 3250

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 2212	. 2 ⊢ (𝜑 → 𝐴 = 𝐵)
3		eqsstrrdi.2	. 2 ⊢ 𝐵 ⊆ 𝐶
4	2, 3	eqsstrdi 3249	1 ⊢ (𝜑 → 𝐴 ⊆ 𝐶)

Syntax hints:   → wi 4   = wceq 1373   ⊆ wss 3170

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 1471  ax-7 1472  ax-gen 1473  ax-ie1 1517  ax-ie2 1518  ax-8 1528  ax-11 1530  ax-4 1534  ax-17 1550  ax-i9 1554  ax-ial 1558  ax-i5r 1559  ax-ext 2188

This theorem depends on definitions:  df-bi 117  df-nf 1485  df-sb 1787  df-clab 2193  df-cleq 2199  df-clel 2202  df-in 3176  df-ss 3183

This theorem is referenced by:  ffvresb  5756  tposss  6345  sbthlemi5  7078  iooval2  10057  telfsumo  11852  structcnvcnv  12923  ressbasssd  12976  txss12  14813  txbasval  14814