Theorem sseqtrrdi 3229

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

Hypotheses

Ref	Expression
sseqtrrdi.1	|- ( ph -> A C_ B )
sseqtrrdi.2	|- C = B

Assertion

Ref	Expression
sseqtrrdi	|- ( ph -> A C_ C )

Proof of Theorem sseqtrrdi

Step	Hyp	Ref	Expression
1		sseqtrrdi.1	. 2 |- ( ph -> A C_ B )
2		sseqtrrdi.2	. . 3 |- C = B
3	2	eqcomi 2197	. 2 |- B = C
4	1, 3	sseqtrdi 3228	1 |- ( ph -> A C_ C )

Syntax hints:   -> wi 4   = wceq 1364   C_ wss 3154

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 1458  ax-7 1459  ax-gen 1460  ax-ie1 1504  ax-ie2 1505  ax-8 1515  ax-11 1517  ax-4 1521  ax-17 1537  ax-i9 1541  ax-ial 1545  ax-i5r 1546  ax-ext 2175

This theorem depends on definitions:  df-bi 117  df-nf 1472  df-sb 1774  df-clab 2180  df-cleq 2186  df-clel 2189  df-in 3160  df-ss 3167

This theorem is referenced by:  iunpw  4512  iotanul  5231  iotass  5233  tfrlem9  6374  tfrlemibfn  6383  tfrlemiubacc  6385  tfrlemi14d  6388  tfr1onlemssrecs  6394  tfr1onlemres  6404  tfrcllemres  6417  exmidfodomrlemr  7264  exmidfodomrlemrALT  7265  uznnssnn  9645  shftfvalg  10965  shftfval  10968  clim2prod  11685  reldvdsrsrg  13591  dvdsrvald  13592  dvdsrex  13597  eltopss  14188  difopn  14287  tgrest  14348  txuni2  14435  tgioo  14733