Theorem fssdm 5372

Description: Expressing that a class is a subclass of the domain of a function expressed in maps-to notation, semi-deduction form. (Contributed by AV, 21-Aug-2022.)

Hypotheses

Ref	Expression
fssdm.d	⊢ 𝐷 ⊆ dom 𝐹
fssdm.f	⊢ (𝜑 → 𝐹:𝐴⟶𝐵)

Assertion

Ref	Expression
fssdm	⊢ (𝜑 → 𝐷 ⊆ 𝐴)

Proof of Theorem fssdm

Step	Hyp	Ref	Expression
1		fssdm.d	. 2 ⊢ 𝐷 ⊆ dom 𝐹
2		fssdm.f	. . 3 ⊢ (𝜑 → 𝐹:𝐴⟶𝐵)
3	2	fdmd 5364	. 2 ⊢ (𝜑 → dom 𝐹 = 𝐴)
4	1, 3	sseqtrid 3203	1 ⊢ (𝜑 → 𝐷 ⊆ 𝐴)

Syntax hints:   → wi 4   ⊆ wss 3127  dom cdm 4620  ⟶wf 5204

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 1445  ax-7 1446  ax-gen 1447  ax-ie1 1491  ax-ie2 1492  ax-8 1502  ax-11 1504  ax-4 1508  ax-17 1524  ax-i9 1528  ax-ial 1532  ax-i5r 1533  ax-ext 2157

This theorem depends on definitions:  df-bi 117  df-nf 1459  df-sb 1761  df-clab 2162  df-cleq 2168  df-clel 2171  df-in 3133  df-ss 3140  df-fn 5211  df-f 5212

This theorem is referenced by:  fisumss  11366  fprodssdc  11564  cnclima  13274  txcnmpt  13324  xmeter  13487