Theorem psseq1i 1561

Description: An equality inference for the proper subclass relationship.

Hypothesis

Ref	Expression
psseq1i.1	⊢ A = B

Assertion

Ref	Expression
psseq1i	⊢ (A ⊂ C ↔ B ⊂ C)

Proof of Theorem psseq1i

Step	Hyp	Ref	Expression
1		psseq1i.1	. 2 ⊢ A = B
2		psseq1 1559	. 2 ⊢ (A = B → (A ⊂ C ↔ B ⊂ C))
3	1, 2	ax-mp 6	1 ⊢ (A ⊂ C ↔ B ⊂ C)

Syntax hints:   ↔ wb 127   = wceq 1091   ⊂ wpss 1488

This theorem is referenced by:  psseq12i 1563

This theorem was proved from axioms:  ax-1 3  ax-2 4  ax-3 5  ax-mp 6  ax-4 673  ax-5 674  ax-6 675  ax-7 676  ax-gen 677  ax-8 798  ax-9 799  ax-10 800  ax-11 801  ax-12 802  ax-16 922  ax-17 925  ax-ext 1074

This theorem depends on definitions:  df-bi 128  df-an 198  df-ex 679  df-sb 853  df-clab 1093  df-cleq 1097  df-clel 1099  df-ne 1192  df-in 1491  df-ss 1492  df-pss 1494

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