Theorem sselii 3194

Description: Membership inference from subclass relationship. (Contributed by NM, 31-May-1999.)

Hypotheses

Ref	Expression
sseli.1	⊢ 𝐴 ⊆ 𝐵
sselii.2	⊢ 𝐶 ∈ 𝐴

Assertion

Ref	Expression
sselii	⊢ 𝐶 ∈ 𝐵

Proof of Theorem sselii

Step	Hyp	Ref	Expression
1		sselii.2	. 2 ⊢ 𝐶 ∈ 𝐴
2		sseli.1	. . 3 ⊢ 𝐴 ⊆ 𝐵
3	2	sseli 3193	. 2 ⊢ (𝐶 ∈ 𝐴 → 𝐶 ∈ 𝐵)
4	1, 3	ax-mp 5	1 ⊢ 𝐶 ∈ 𝐵

Syntax hints:   ∈ wcel 2177   ⊆ wss 3170

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-5 1471  ax-7 1472  ax-gen 1473  ax-ie1 1517  ax-ie2 1518  ax-8 1528  ax-11 1530  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-nf 1485  df-sb 1787  df-clab 2193  df-cleq 2199  df-clel 2202  df-in 3176  df-ss 3183

This theorem is referenced by:  brtpos0  6351  ax1cn  7994  recni  8104  0xr  8139  pnfxr  8145  nn0rei  9326  0xnn0  9384  nnzi  9413  nn0zi  9414  mincncf  15163  lgsdir2lem3  15582