Theorem ss2in 4195

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 4192	. 2 ⊢ (𝐴 ⊆ 𝐵 → (𝐴 ∩ 𝐶) ⊆ (𝐵 ∩ 𝐶))
2		sslin 4193	. 2 ⊢ (𝐶 ⊆ 𝐷 → (𝐵 ∩ 𝐶) ⊆ (𝐵 ∩ 𝐷))
3	1, 2	sylan9ss 3948	1 ⊢ ((𝐴 ⊆ 𝐵 ∧ 𝐶 ⊆ 𝐷) → (𝐴 ∩ 𝐶) ⊆ (𝐵 ∩ 𝐷))

Syntax hints:   → wi 4   ∧ wa 395   ∩ cin 3901   ⊆ wss 3902

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1796  ax-4 1810  ax-5 1911  ax-6 1968  ax-7 2009  ax-8 2113  ax-9 2121  ax-ext 2703

This theorem depends on definitions:  df-bi 207  df-an 396  df-tru 1544  df-ex 1781  df-sb 2068  df-clab 2710  df-cleq 2723  df-clel 2806  df-rab 3396  df-v 3438  df-in 3909  df-ss 3919

This theorem is referenced by:  disjxiun  5088  f1un  6783  strleun  17068  dprdss  19944  dprd2da  19957  ablfac1b  19985  tgcl  22885  innei  23041  hausnei2  23269  bwth  23326  fbssfi  23753  fbunfip  23785  fgcl  23794  blin2  24345  vtxdun  29461  vtxdginducedm1  29523  5oai  31639  mayetes3i  31707  mdsl0  32288  neibastop1  36399  ismblfin  37707  heibor1lem  37855  pl42lem2N  40025  pl42lem3N  40026  ntrk2imkb  44076  ssin0  45098  iscnrm3llem2  48987