Theorem sseq1d 3027

Description: An equality deduction for the subclass relationship. (Contributed by NM, 14-Aug-1994.)

Hypothesis

Ref	Expression
sseq1d.1	⊢ (𝜑 → 𝐴 = 𝐵)

Assertion

Ref	Expression
sseq1d	⊢ (𝜑 → (𝐴 ⊆ 𝐶 ↔ 𝐵 ⊆ 𝐶))

Proof of Theorem sseq1d

Step	Hyp	Ref	Expression
1		sseq1d.1	. 2 ⊢ (𝜑 → 𝐴 = 𝐵)
2		sseq1 3021	. 2 ⊢ (𝐴 = 𝐵 → (𝐴 ⊆ 𝐶 ↔ 𝐵 ⊆ 𝐶))
3	1, 2	syl 14	1 ⊢ (𝜑 → (𝐴 ⊆ 𝐶 ↔ 𝐵 ⊆ 𝐶))

Syntax hints:   → wi 4   ↔ wb 103   = wceq 1285   ⊆ wss 2974

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-5 1377  ax-7 1378  ax-gen 1379  ax-ie1 1423  ax-ie2 1424  ax-8 1436  ax-11 1438  ax-4 1441  ax-17 1460  ax-i9 1464  ax-ial 1468  ax-i5r 1469  ax-ext 2064

This theorem depends on definitions:  df-bi 115  df-nf 1391  df-sb 1687  df-clab 2069  df-cleq 2075  df-clel 2078  df-in 2980  df-ss 2987

This theorem is referenced by:  sseq12d  3029  eqsstrd  3034  snssg  3530  ssiun2s  3730  treq  3889  onsucsssucexmid  4278  funimass1  5007  feq1  5061  sbcfg  5076  fvmptssdm  5287  fvimacnvi  5313  nnsucsssuc  6136  ereq1  6179