tc00 - Metamath Proof Explorer

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Theorem tc00 9213

Description: The transitive closure is empty iff its argument is. Proof suggested by Gérard Lang. (Contributed by Mario Carneiro, 4-Jun-2015.)

**Assertion**
Ref	Expression
tc00	⊢ (𝐴 ∈ 𝑉 → ((TC‘𝐴) = ∅ ↔ 𝐴 = ∅))

**Proof of Theorem tc00**
Step	Hyp	Ref	Expression
1		tcid 9204	. . 3 ⊢ (𝐴 ∈ 𝑉 → 𝐴 ⊆ (TC‘𝐴))
2		sseq0 4294	. . . 4 ⊢ ((𝐴 ⊆ (TC‘𝐴) ∧ (TC‘𝐴) = ∅) → 𝐴 = ∅)
3	2	ex 417	. . 3 ⊢ (𝐴 ⊆ (TC‘𝐴) → ((TC‘𝐴) = ∅ → 𝐴 = ∅))
4	1, 3	syl 17	. 2 ⊢ (𝐴 ∈ 𝑉 → ((TC‘𝐴) = ∅ → 𝐴 = ∅))
5		fveq2 6656	. . 3 ⊢ (𝐴 = ∅ → (TC‘𝐴) = (TC‘∅))
6		tc0 9212	. . 3 ⊢ (TC‘∅) = ∅
7	5, 6	eqtrdi 2810	. 2 ⊢ (𝐴 = ∅ → (TC‘𝐴) = ∅)
8	4, 7	impbid1 228	1 ⊢ (𝐴 ∈ 𝑉 → ((TC‘𝐴) = ∅ ↔ 𝐴 = ∅))

Colors of variables: wff setvar class

Syntax hints: → wi 4 ↔ wb 209 = wceq 1539 ∈ wcel 2112 ⊆ wss 3859 ∅c0 4226 ‘cfv 6333 TCctc 9201

This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1798 ax-4 1812 ax-5 1912 ax-6 1971 ax-7 2016 ax-8 2114 ax-9 2122 ax-10 2143 ax-11 2159 ax-12 2176 ax-ext 2730 ax-rep 5154 ax-sep 5167 ax-nul 5174 ax-pr 5296 ax-un 7457 ax-inf2 9127

This theorem depends on definitions: df-bi 210 df-an 401 df-or 846 df-3or 1086 df-3an 1087 df-tru 1542 df-fal 1552 df-ex 1783 df-nf 1787 df-sb 2071 df-mo 2558 df-eu 2589 df-clab 2737 df-cleq 2751 df-clel 2831 df-nfc 2902 df-ne 2953 df-ral 3076 df-rex 3077 df-reu 3078 df-rab 3080 df-v 3412 df-sbc 3698 df-csb 3807 df-dif 3862 df-un 3864 df-in 3866 df-ss 3876 df-pss 3878 df-nul 4227 df-if 4419 df-pw 4494 df-sn 4521 df-pr 4523 df-tp 4525 df-op 4527 df-uni 4797 df-int 4837 df-iun 4883 df-br 5031 df-opab 5093 df-mpt 5111 df-tr 5137 df-id 5428 df-eprel 5433 df-po 5441 df-so 5442 df-fr 5481 df-we 5483 df-xp 5528 df-rel 5529 df-cnv 5530 df-co 5531 df-dm 5532 df-rn 5533 df-res 5534 df-ima 5535 df-pred 6124 df-ord 6170 df-on 6171 df-lim 6172 df-suc 6173 df-iota 6292 df-fun 6335 df-fn 6336 df-f 6337 df-f1 6338 df-fo 6339 df-f1o 6340 df-fv 6341 df-om 7578 df-wrecs 7955 df-recs 8016 df-rdg 8054 df-tc 9202

This theorem is referenced by: (None)