Theorem eqsstrri 3260

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 2235	. 2 ⊢ 𝐴 = 𝐵
3		eqsstr3.2	. 2 ⊢ 𝐵 ⊆ 𝐶
4	2, 3	eqsstri 3259	1 ⊢ 𝐴 ⊆ 𝐶

Syntax hints:   = wceq 1397   ⊆ wss 3200

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 1495  ax-7 1496  ax-gen 1497  ax-ie1 1541  ax-ie2 1542  ax-8 1552  ax-11 1554  ax-4 1558  ax-17 1574  ax-i9 1578  ax-ial 1582  ax-i5r 1583  ax-ext 2213

This theorem depends on definitions:  df-bi 117  df-nf 1509  df-sb 1811  df-clab 2218  df-cleq 2224  df-clel 2227  df-in 3206  df-ss 3213

This theorem is referenced by:  inss2  3428  dmv  4947  resasplitss  5516  ofrfval  6243  ofvalg  6244  ofrval  6245  off  6247  ofres  6249  ofco  6253  dftpos4  6428  smores2  6459  caseinj  7287  djuinj  7304  bcm1k  11021  bcpasc  11027  nninfctlemfo  12610