Theorem ssind 3387

Description: A deduction showing that a subclass of two classes is a subclass of their intersection. (Contributed by Jonathan Ben-Naim, 3-Jun-2011.)

Hypotheses

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

Assertion

Ref	Expression
ssind	|- ( ph -> A C_ ( B i^i C ) )

Proof of Theorem ssind

Step	Hyp	Ref	Expression
1		ssind.1	. 2 |- ( ph -> A C_ B )
2		ssind.2	. 2 |- ( ph -> A C_ C )
3		ssin 3385	. . 3 |- ( ( A C_ B /\ A C_ C ) <-> A C_ ( B i^i C ) )
4	3	biimpi 120	. 2 |- ( ( A C_ B /\ A C_ C ) -> A C_ ( B i^i C ) )
5	1, 2, 4	syl2anc 411	1 |- ( ph -> A C_ ( B i^i C ) )

Syntax hints:   -> wi 4   /\ wa 104   i^i cin 3156   C_ wss 3157

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-io 710  ax-5 1461  ax-7 1462  ax-gen 1463  ax-ie1 1507  ax-ie2 1508  ax-8 1518  ax-10 1519  ax-11 1520  ax-i12 1521  ax-bndl 1523  ax-4 1524  ax-17 1540  ax-i9 1544  ax-ial 1548  ax-i5r 1549  ax-ext 2178

This theorem depends on definitions:  df-bi 117  df-tru 1367  df-nf 1475  df-sb 1777  df-clab 2183  df-cleq 2189  df-clel 2192  df-nfc 2328  df-v 2765  df-in 3163  df-ss 3170

This theorem is referenced by:  ntrin  14360  lmss  14482