Theorem fssdmd 6729

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

Hypotheses

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

Assertion

Ref	Expression
fssdmd	⊢ (𝜑 → 𝐷 ⊆ 𝐴)

Proof of Theorem fssdmd

Step	Hyp	Ref	Expression
1		fssdmd.d	. 2 ⊢ (𝜑 → 𝐷 ⊆ dom 𝐹)
2		fssdmd.f	. . 3 ⊢ (𝜑 → 𝐹:𝐴⟶𝐵)
3	2	fdmd 6721	. 2 ⊢ (𝜑 → dom 𝐹 = 𝐴)
4	1, 3	sseqtrd 3944	1 ⊢ (𝜑 → 𝐷 ⊆ 𝐴)

This proof depends on syntax axioms:   → wi 4   ⊆ wss 3895  dom cdm 5650  ⟶wf 6535

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1827  ax-4 1841  ax-5 1942  ax-6 1999  ax-7 2040  ax-9 2154  ax-ext 2732

This proof depends on definitions:  df-bi 210  df-an 402  df-ex 1812  df-cleq 2752  df-ss 3896  df-fn 6542  df-f 6543

This theorem is used by:  ordtypelem7  9522  vdwlem11  17175  gsumzoppg  20164  taylfvallem1  26690  taylply2  26701  taylply  26702  dvtaylp  26703  dvntaylp0  26705  taylthlem1  26706  taylthlem2  26707  tocyccntz  33752  omssubadd  34979