Theorem 3sstr3d 3967

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 3954	. 2 ⊢ (𝜑 → (𝐴 ⊆ 𝐵 ↔ 𝐶 ⊆ 𝐷))
5	1, 4	mpbid 231	1 ⊢ (𝜑 → 𝐶 ⊆ 𝐷)

Syntax hints:   → wi 4   = wceq 1539   ⊆ wss 3887

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 1913  ax-6 1971  ax-7 2011  ax-8 2108  ax-9 2116  ax-ext 2709

This theorem depends on definitions:  df-bi 206  df-an 397  df-tru 1542  df-ex 1783  df-sb 2068  df-clab 2716  df-cleq 2730  df-clel 2816  df-v 3434  df-in 3894  df-ss 3904

This theorem is referenced by:  cnvtsr  18306  dprdss  19632  dprd2da  19645  dmdprdsplit2lem  19648  mplind  21278  txcmplem1  22792  setsmstopn  23633  tngtopn  23814  bcthlem2  24489  bcthlem4  24491  uniiccvol  24744  dyadmaxlem  24761  dvlip2  25159  dvne0  25175  shlej2  29723  gsumzresunsn  31314  pmtrcnel2  31359  cyc3co2  31407  fedgmullem1  31710  hauseqcn  31848  bnd2lem  35949  heiborlem8  35976  dochord  39384  lclkrlem2p  39536  mapdsn  39655  hbtlem5  40953  fvmptiunrelexplb0d  41292  fvmptiunrelexplb1d  41294  isclatd  46269