Theorem 3sstr3d 3647

Description: Substitution of equality into both sides of a subclass relationship. (Contributed by NM, 1-Oct-2000.)

Hypotheses

Ref	Expression
3sstr3d.1	⊢ (𝜑 → 𝐴 ⊆ 𝐵)
3sstr3d.2	⊢ (𝜑 → 𝐴 = 𝐶)
3sstr3d.3	⊢ (𝜑 → 𝐵 = 𝐷)

Assertion

Ref	Expression
3sstr3d	⊢ (𝜑 → 𝐶 ⊆ 𝐷)

Proof of Theorem 3sstr3d

Step	Hyp	Ref	Expression
1		3sstr3d.1	. 2 ⊢ (𝜑 → 𝐴 ⊆ 𝐵)
2		3sstr3d.2	. . 3 ⊢ (𝜑 → 𝐴 = 𝐶)
3		3sstr3d.3	. . 3 ⊢ (𝜑 → 𝐵 = 𝐷)
4	2, 3	sseq12d 3634	. 2 ⊢ (𝜑 → (𝐴 ⊆ 𝐵 ↔ 𝐶 ⊆ 𝐷))
5	1, 4	mpbid 222	1 ⊢ (𝜑 → 𝐶 ⊆ 𝐷)

Syntax hints:   → wi 4   = wceq 1483   ⊆ wss 3574

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-9 1999  ax-10 2019  ax-11 2034  ax-12 2047  ax-13 2246  ax-ext 2602

This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-tru 1486  df-ex 1705  df-nf 1710  df-sb 1881  df-clab 2609  df-cleq 2615  df-clel 2618  df-in 3581  df-ss 3588

This theorem is referenced by:  cnvtsr  17222  dprdss  18428  dprd2da  18441  dmdprdsplit2lem  18444  mplind  19502  txcmplem1  21444  setsmstopn  22283  tngtopn  22454  bcthlem2  23122  bcthlem4  23124  uniiccvol  23348  dyadmaxlem  23365  dvlip2  23758  dvne0  23774  shlej2  28220  hauseqcn  29941  bnd2lem  33590  heiborlem8  33617  dochord  36659  lclkrlem2p  36811  mapdsn  36930  hbtlem5  37698  fvmptiunrelexplb0d  37976  fvmptiunrelexplb1d  37978