Theorem eqsstrri 3271

Description: Substitution of equality into a subclass relationship. (Contributed by NM, 19-Oct-1999.)

Hypotheses

Ref	Expression
eqsstr3.1	⊢ 𝐵 = 𝐴
eqsstr3.2	⊢ 𝐵 ⊆ 𝐶

Assertion

Ref	Expression
eqsstrri	⊢ 𝐴 ⊆ 𝐶

Proof of Theorem eqsstrri

Step	Hyp	Ref	Expression
1		eqsstr3.1	. . 3 ⊢ 𝐵 = 𝐴
2	1	eqcomi 2236	. 2 ⊢ 𝐴 = 𝐵
3		eqsstr3.2	. 2 ⊢ 𝐵 ⊆ 𝐶
4	2, 3	eqsstri 3270	1 ⊢ 𝐴 ⊆ 𝐶

Syntax hints:   = wceq 1398   ⊆ wss 3211

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 2214

This theorem depends on definitions:  df-bi 117  df-nf 1510  df-sb 1812  df-clab 2219  df-cleq 2225  df-clel 2228  df-in 3217  df-ss 3224

This theorem is referenced by:  inss2  3442  dmv  4972  resasplitss  5544  ofrfval  6275  ofvalg  6276  ofrval  6277  off  6279  ofres  6281  ofco  6285  dftpos4  6494  smores2  6525  caseinj  7380  djuinj  7397  bcm1k  11122  bcpasc  11128  nninfctlemfo  12736