Theorem ss2in 4237

Description: Intersection of subclasses. (Contributed by NM, 5-May-2000.)

Assertion

Ref	Expression
ss2in	⊢ ((𝐴 ⊆ 𝐵 ∧ 𝐶 ⊆ 𝐷) → (𝐴 ∩ 𝐶) ⊆ (𝐵 ∩ 𝐷))

Proof of Theorem ss2in

Step	Hyp	Ref	Expression
1		ssrin 4234	. 2 ⊢ (𝐴 ⊆ 𝐵 → (𝐴 ∩ 𝐶) ⊆ (𝐵 ∩ 𝐶))
2		sslin 4235	. 2 ⊢ (𝐶 ⊆ 𝐷 → (𝐵 ∩ 𝐶) ⊆ (𝐵 ∩ 𝐷))
3	1, 2	sylan9ss 3996	1 ⊢ ((𝐴 ⊆ 𝐵 ∧ 𝐶 ⊆ 𝐷) → (𝐴 ∩ 𝐶) ⊆ (𝐵 ∩ 𝐷))

Syntax hints:   → wi 4   ∧ wa 397   ∩ cin 3948   ⊆ wss 3949

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1798  ax-4 1812  ax-5 1914  ax-6 1972  ax-7 2012  ax-8 2109  ax-9 2117  ax-ext 2704

This theorem depends on definitions:  df-bi 206  df-an 398  df-tru 1545  df-ex 1783  df-sb 2069  df-clab 2711  df-cleq 2725  df-clel 2811  df-rab 3434  df-v 3477  df-in 3956  df-ss 3966

This theorem is referenced by:  disjxiun  5146  f1un  6854  undomOLD  9060  strleun  17090  dprdss  19899  dprd2da  19912  ablfac1b  19940  tgcl  22472  innei  22629  hausnei2  22857  bwth  22914  fbssfi  23341  fbunfip  23373  fgcl  23382  blin2  23935  vtxdun  28738  vtxdginducedm1  28800  5oai  30914  mayetes3i  30982  mdsl0  31563  neibastop1  35244  ismblfin  36529  heibor1lem  36677  pl42lem2N  38851  pl42lem3N  38852  ntrk2imkb  42788  ssin0  43742  iscnrm3llem2  47583