Theorem fss 5292

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 3109	. . . . 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 335	. . 3 ⊢ (𝐵 ⊆ 𝐶 → ((𝐹 Fn 𝐴 ∧ ran 𝐹 ⊆ 𝐵) → (𝐹 Fn 𝐴 ∧ ran 𝐹 ⊆ 𝐶)))
4		df-f 5135	. . 3 ⊢ (𝐹:𝐴⟶𝐵 ↔ (𝐹 Fn 𝐴 ∧ ran 𝐹 ⊆ 𝐵))
5		df-f 5135	. . 3 ⊢ (𝐹:𝐴⟶𝐶 ↔ (𝐹 Fn 𝐴 ∧ ran 𝐹 ⊆ 𝐶))
6	3, 4, 5	3imtr4g 204	. 2 ⊢ (𝐵 ⊆ 𝐶 → (𝐹:𝐴⟶𝐵 → 𝐹:𝐴⟶𝐶))
7	6	impcom 124	1 ⊢ ((𝐹:𝐴⟶𝐵 ∧ 𝐵 ⊆ 𝐶) → 𝐹:𝐴⟶𝐶)

Syntax hints:   → wi 4   ∧ wa 103   ⊆ wss 3076  ran crn 4548   Fn wfn 5126  ⟶wf 5127

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-5 1424  ax-7 1425  ax-gen 1426  ax-ie1 1470  ax-ie2 1471  ax-8 1483  ax-11 1485  ax-4 1488  ax-17 1507  ax-i9 1511  ax-ial 1515  ax-i5r 1516  ax-ext 2122

This theorem depends on definitions:  df-bi 116  df-nf 1438  df-sb 1737  df-clab 2127  df-cleq 2133  df-clel 2136  df-in 3082  df-ss 3089  df-f 5135

This theorem is referenced by:  fssd  5293  fconst6g  5329  f1ss  5342  ffoss  5407  fsn2  5602  ofco  6008  tposf2  6173  issmo2  6194  smoiso  6207  mapsn  6592  ssdomg  6680  omp1eomlem  6987  1fv  9947  fxnn0nninf  10242  abscn2  11116  recn2  11118  imcn2  11119  climabs  11121  climre  11123  climim  11124  fsumre  11273  fsumim  11274  ismet2  12562  dvfre  12882  dvrecap  12885