Theorem resdm 5052

Description: A relation restricted to its domain equals itself. (Contributed by NM, 12-Dec-2006.)

Assertion

Ref	Expression
resdm	⊢ (Rel 𝐴 → (𝐴 ↾ dom 𝐴) = 𝐴)

Proof of Theorem resdm

Step	Hyp	Ref	Expression
1		ssid 3247	. 2 ⊢ dom 𝐴 ⊆ dom 𝐴
2		relssres 5051	. 2 ⊢ ((Rel 𝐴 ∧ dom 𝐴 ⊆ dom 𝐴) → (𝐴 ↾ dom 𝐴) = 𝐴)
3	1, 2	mpan2 425	1 ⊢ (Rel 𝐴 → (𝐴 ↾ dom 𝐴) = 𝐴)

Syntax hints:   → wi 4   = wceq 1397   ⊆ wss 3200  dom cdm 4725   ↾ cres 4727  Rel wrel 4730

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-io 716  ax-5 1495  ax-7 1496  ax-gen 1497  ax-ie1 1541  ax-ie2 1542  ax-8 1552  ax-10 1553  ax-11 1554  ax-i12 1555  ax-bndl 1557  ax-4 1558  ax-17 1574  ax-i9 1578  ax-ial 1582  ax-i5r 1583  ax-14 2205  ax-ext 2213  ax-sep 4207  ax-pow 4264  ax-pr 4299

This theorem depends on definitions:  df-bi 117  df-3an 1006  df-tru 1400  df-nf 1509  df-sb 1811  df-clab 2218  df-cleq 2224  df-clel 2227  df-nfc 2363  df-ral 2515  df-rex 2516  df-v 2804  df-un 3204  df-in 3206  df-ss 3213  df-pw 3654  df-sn 3675  df-pr 3676  df-op 3678  df-br 4089  df-opab 4151  df-xp 4731  df-rel 4732  df-dm 4735  df-res 4737

This theorem is referenced by:  resindm  5055  resdm2  5227  relresfld  5266  relcoi1  5268  funimaexg  5414  fnex  5875  dftpos2  6426  pmresg  6844  dif1en  7067