Theorem fss 5415

Description: Expanding the codomain of a mapping. (Contributed by NM, 10-May-1998.) (Proof shortened by Andrew Salmon, 17-Sep-2011.)

Assertion

Ref	Expression
fss	⊢ ((𝐹:𝐴⟶𝐵 ∧ 𝐵 ⊆ 𝐶) → 𝐹:𝐴⟶𝐶)

Proof of Theorem fss

Step	Hyp	Ref	Expression
1		sstr2 3186	. . . . 5 ⊢ (ran 𝐹 ⊆ 𝐵 → (𝐵 ⊆ 𝐶 → ran 𝐹 ⊆ 𝐶))
2	1	com12 30	. . . 4 ⊢ (𝐵 ⊆ 𝐶 → (ran 𝐹 ⊆ 𝐵 → ran 𝐹 ⊆ 𝐶))
3	2	anim2d 337	. . 3 ⊢ (𝐵 ⊆ 𝐶 → ((𝐹 Fn 𝐴 ∧ ran 𝐹 ⊆ 𝐵) → (𝐹 Fn 𝐴 ∧ ran 𝐹 ⊆ 𝐶)))
4		df-f 5258	. . 3 ⊢ (𝐹:𝐴⟶𝐵 ↔ (𝐹 Fn 𝐴 ∧ ran 𝐹 ⊆ 𝐵))
5		df-f 5258	. . 3 ⊢ (𝐹:𝐴⟶𝐶 ↔ (𝐹 Fn 𝐴 ∧ ran 𝐹 ⊆ 𝐶))
6	3, 4, 5	3imtr4g 205	. 2 ⊢ (𝐵 ⊆ 𝐶 → (𝐹:𝐴⟶𝐵 → 𝐹:𝐴⟶𝐶))
7	6	impcom 125	1 ⊢ ((𝐹:𝐴⟶𝐵 ∧ 𝐵 ⊆ 𝐶) → 𝐹:𝐴⟶𝐶)

Syntax hints:   → wi 4   ∧ wa 104   ⊆ wss 3153  ran crn 4660   Fn wfn 5249  ⟶wf 5250

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 1458  ax-7 1459  ax-gen 1460  ax-ie1 1504  ax-ie2 1505  ax-8 1515  ax-11 1517  ax-4 1521  ax-17 1537  ax-i9 1541  ax-ial 1545  ax-i5r 1546  ax-ext 2175

This theorem depends on definitions:  df-bi 117  df-nf 1472  df-sb 1774  df-clab 2180  df-cleq 2186  df-clel 2189  df-in 3159  df-ss 3166  df-f 5258

This theorem is referenced by:  fssd  5416  fconst6g  5452  f1ss  5465  ffoss  5532  fsn2  5732  ofco  6149  tposf2  6321  issmo2  6342  smoiso  6355  mapsn  6744  ssdomg  6832  omp1eomlem  7153  1fv  10205  fxnn0nninf  10510  abscn2  11458  recn2  11460  imcn2  11461  climabs  11463  climre  11465  climim  11466  fsumre  11615  fsumim  11616  resmhm2  13060  ismet2  14522  dvfre  14859  dvrecap  14862  elplyr  14886  lgsfcl  15124