Theorem sseqtrrdi 3286

Description: A chained subclass and equality deduction. (Contributed by NM, 25-Apr-2004.)

Hypotheses

Ref	Expression
sseqtrrdi.1	⊢ (𝜑 → 𝐴 ⊆ 𝐵)
sseqtrrdi.2	⊢ 𝐶 = 𝐵

Assertion

Ref	Expression
sseqtrrdi	⊢ (𝜑 → 𝐴 ⊆ 𝐶)

Proof of Theorem sseqtrrdi

Step	Hyp	Ref	Expression
1		sseqtrrdi.1	. 2 ⊢ (𝜑 → 𝐴 ⊆ 𝐵)
2		sseqtrrdi.2	. . 3 ⊢ 𝐶 = 𝐵
3	2	eqcomi 2236	. 2 ⊢ 𝐵 = 𝐶
4	1, 3	sseqtrdi 3285	1 ⊢ (𝜑 → 𝐴 ⊆ 𝐶)

Syntax hints:   → wi 4   = wceq 1398   ⊆ wss 3210

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 3216  df-ss 3223

This theorem is referenced by:  iunpw  4600  iotanul  5327  iotass  5329  tfrlem9  6549  tfrlemibfn  6558  tfrlemiubacc  6560  tfrlemi14d  6563  tfr1onlemssrecs  6569  tfr1onlemres  6579  tfrcllemres  6592  exmidfodomrlemr  7504  exmidfodomrlemrALT  7505  uznnssnn  9905  pfxccatpfx2  11422  shftfvalg  11496  shftfval  11499  clim2prod  12218  dvdsrvald  14227  dvdsrex  14232  eltopss  14861  difopn  14960  tgrest  15021  txuni2  15108  tgioo  15406  plycoeid3  15609