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| Mirrors > Home > MPE Home > Th. List > Mathboxes > cfsetsnfsetf1o | Structured version Visualization version GIF version | ||
| Description: The mapping of the class of singleton functions into the class of constant functions is a bijection. (Contributed by AV, 14-Sep-2024.) |
| Ref | Expression |
|---|---|
| cfsetsnfsetfv.f | ⊢ 𝐹 = {𝑓 ∣ (𝑓:𝐴⟶𝐵 ∧ ∃𝑏 ∈ 𝐵 ∀𝑧 ∈ 𝐴 (𝑓‘𝑧) = 𝑏)} |
| cfsetsnfsetfv.g | ⊢ 𝐺 = {𝑥 ∣ 𝑥:{𝑌}⟶𝐵} |
| cfsetsnfsetfv.h | ⊢ 𝐻 = (𝑔 ∈ 𝐺 ↦ (𝑎 ∈ 𝐴 ↦ (𝑔‘𝑌))) |
| Ref | Expression |
|---|---|
| cfsetsnfsetf1o | ⊢ ((𝐴 ∈ 𝑉 ∧ 𝑌 ∈ 𝐴) → 𝐻:𝐺–1-1-onto→𝐹) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | cfsetsnfsetfv.f | . . 3 ⊢ 𝐹 = {𝑓 ∣ (𝑓:𝐴⟶𝐵 ∧ ∃𝑏 ∈ 𝐵 ∀𝑧 ∈ 𝐴 (𝑓‘𝑧) = 𝑏)} | |
| 2 | cfsetsnfsetfv.g | . . 3 ⊢ 𝐺 = {𝑥 ∣ 𝑥:{𝑌}⟶𝐵} | |
| 3 | cfsetsnfsetfv.h | . . 3 ⊢ 𝐻 = (𝑔 ∈ 𝐺 ↦ (𝑎 ∈ 𝐴 ↦ (𝑔‘𝑌))) | |
| 4 | 1, 2, 3 | cfsetsnfsetf1 48268 | . 2 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝑌 ∈ 𝐴) → 𝐻:𝐺–1-1→𝐹) |
| 5 | 1, 2, 3 | cfsetsnfsetfo 48269 | . 2 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝑌 ∈ 𝐴) → 𝐻:𝐺–onto→𝐹) |
| 6 | df-f1o 6553 | . 2 ⊢ (𝐻:𝐺–1-1-onto→𝐹 ↔ (𝐻:𝐺–1-1→𝐹 ∧ 𝐻:𝐺–onto→𝐹)) | |
| 7 | 4, 5, 6 | sylanbrc 595 | 1 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝑌 ∈ 𝐴) → 𝐻:𝐺–1-1-onto→𝐹) |
| Colors of variables: wff setvar class |
| This proof depends on syntax axioms: → wi 4 ∧ wa 401 = wceq 1569 ∈ wcel 2146 {cab 2741 ∀wral 3079 ∃wrex 3089 {csn 4587 ↦ cmpt 5188 ⟶wf 6542 –1-1→wf1 6543 –onto→wfo 6544 –1-1-onto→wf1o 6545 ‘cfv 6546 |
| 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 1944 ax-6 2001 ax-7 2042 ax-8 2148 ax-9 2156 ax-10 2179 ax-11 2196 ax-12 2215 ax-ext 2735 ax-rep 5234 ax-sep 5251 ax-nul 5262 ax-pr 5394 |
| This proof depends on definitions: df-bi 210 df-an 402 df-or 862 df-3an 1105 df-tru 1572 df-fal 1582 df-ex 1812 df-nf 1816 df-sb 2101 df-mo 2567 df-eu 2597 df-clab 2742 df-cleq 2755 df-clel 2838 df-nfc 2912 df-ne 2959 df-ral 3080 df-rex 3090 df-reu 3369 df-rab 3416 df-v 3455 df-sbc 3742 df-csb 3851 df-ss 3900 df-dif 4049 df-in 4093 df-un 4153 df-nul 4281 df-if 4485 df-sn 4588 df-pr 4590 df-op 4838 df-uni 4870 df-iun 4955 df-br 5106 df-opab 5170 df-mpt 5189 df-id 5549 df-xp 5660 df-rel 5661 df-cnv 5662 df-co 5663 df-dm 5664 df-rn 5665 df-res 5666 df-ima 5667 df-iota 6500 df-fun 6548 df-fn 6549 df-f 6550 df-f1 6551 df-fo 6552 df-f1o 6553 df-fv 6554 |
| This theorem is used by: fsetprcnexALT 48271 |
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