Theorem sseq1d 3026

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 3020	. 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 1284   ⊆ wss 2973

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 1376  ax-7 1377  ax-gen 1378  ax-ie1 1422  ax-ie2 1423  ax-8 1435  ax-11 1437  ax-4 1440  ax-17 1459  ax-i9 1463  ax-ial 1467  ax-i5r 1468  ax-ext 2063

This theorem depends on definitions:  df-bi 115  df-nf 1390  df-sb 1686  df-clab 2068  df-cleq 2074  df-clel 2077  df-in 2979  df-ss 2986

This theorem is referenced by:  sseq12d  3028  eqsstrd  3033  snssg  3522  ssiun2s  3722  treq  3881  onsucsssucexmid  4270  funimass1  4996  feq1  5050  sbcfg  5065  fvmptssdm  5276  fvimacnvi  5302  nnsucsssuc  6094  ereq1  6136