Theorem unissi 3879

Description: Subclass relationship for subclass union. Inference form of uniss 3877. (Contributed by David Moews, 1-May-2017.)

Hypothesis

Ref	Expression
unissi.1	⊢ 𝐴 ⊆ 𝐵

Assertion

Ref	Expression
unissi	⊢ ∪ 𝐴 ⊆ ∪ 𝐵

Proof of Theorem unissi

Step	Hyp	Ref	Expression
1		unissi.1	. 2 ⊢ 𝐴 ⊆ 𝐵
2		uniss 3877	. 2 ⊢ (𝐴 ⊆ 𝐵 → ∪ 𝐴 ⊆ ∪ 𝐵)
3	1, 2	ax-mp 5	1 ⊢ ∪ 𝐴 ⊆ ∪ 𝐵

Syntax hints:   ⊆ wss 3170  ∪ cuni 3856

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 711  ax-5 1471  ax-7 1472  ax-gen 1473  ax-ie1 1517  ax-ie2 1518  ax-8 1528  ax-10 1529  ax-11 1530  ax-i12 1531  ax-bndl 1533  ax-4 1534  ax-17 1550  ax-i9 1554  ax-ial 1558  ax-i5r 1559  ax-ext 2188

This theorem depends on definitions:  df-bi 117  df-tru 1376  df-nf 1485  df-sb 1787  df-clab 2193  df-cleq 2199  df-clel 2202  df-nfc 2338  df-v 2775  df-in 3176  df-ss 3183  df-uni 3857

This theorem is referenced by:  unidif  3888  unixpss  4796  tfrcllemssrecs  6451  tgvalex  13170  tgval2  14598  eltg4i  14602  ntrss2  14668  isopn3  14672