Theorem abssi 3341

Description: Inference of abstraction subclass from implication. (Contributed by NM, 20-Jan-2006.)

Hypothesis

Ref	Expression
abssi.1	|- (ph -> x e. A)

Assertion

Ref	Expression
abssi	|- {x | ph} C_ A

Distinct variable group:   x,A

Allowed substitution hint:   ph(x)

Proof of Theorem abssi

Step	Hyp	Ref	Expression
1		abssi.1	. . 3 |- (ph -> x e. A)
2	1	ss2abi 3338	. 2 |- {x | ph} C_ {x | x e. A}
3		abid2 2470	. 2 |- {x | x e. A} = A
4	2, 3	sseqtri 3303	1 |- {x | ph} C_ A

Syntax hints:   -> wi 4   e. wcel 1710  {cab 2339   C_ wss 3257

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1546  ax-5 1557  ax-17 1616  ax-9 1654  ax-8 1675  ax-6 1729  ax-7 1734  ax-11 1746  ax-12 1925  ax-ext 2334

This theorem depends on definitions:  df-bi 177  df-or 359  df-an 360  df-nan 1288  df-tru 1319  df-ex 1542  df-nf 1545  df-sb 1649  df-clab 2340  df-cleq 2346  df-clel 2349  df-nfc 2478  df-v 2861  df-nin 3211  df-compl 3212  df-in 3213  df-ss 3259

This theorem is referenced by:  ssab2  3350  abf  3584  intab  3956  opkabssvvk  4208  fvclss  5462  mapsspw  6022  spacssnc  6284