Theorem isfld2 38755

Description: Obsolete theorem, use isfld 20903 instead. The predicate "is a field". (Contributed by Jeff Madsen, 10-Jun-2010.) (Proof modification is discouraged.) (New usage is discouraged.)

Assertion

Ref	Expression
isfld2	⊢ (𝐾 ∈ Fld ↔ (𝐾 ∈ DivRingOps ∧ 𝐾 ∈ CRingOps))

Proof of Theorem isfld2

Step	Hyp	Ref	Expression
1		flddivrng 38749	. . 3 ⊢ (𝐾 ∈ Fld → 𝐾 ∈ DivRingOps)
2		fldcrngo 38754	. . 3 ⊢ (𝐾 ∈ Fld → 𝐾 ∈ CRingOps)
3	1, 2	jca 521	. 2 ⊢ (𝐾 ∈ Fld → (𝐾 ∈ DivRingOps ∧ 𝐾 ∈ CRingOps))
4		iscrngo 38746	. . . 4 ⊢ (𝐾 ∈ CRingOps ↔ (𝐾 ∈ RingOps ∧ 𝐾 ∈ Com2))
5	4	simprbi 503	. . 3 ⊢ (𝐾 ∈ CRingOps → 𝐾 ∈ Com2)
6		elin 3915	. . . . 5 ⊢ (𝐾 ∈ (DivRingOps ∩ Com2) ↔ (𝐾 ∈ DivRingOps ∧ 𝐾 ∈ Com2))
7	6	biimpri 231	. . . 4 ⊢ ((𝐾 ∈ DivRingOps ∧ 𝐾 ∈ Com2) → 𝐾 ∈ (DivRingOps ∩ Com2))
8		df-fld 38742	. . . 4 ⊢ Fld = (DivRingOps ∩ Com2)
9	7, 8	eleqtrrdi 2871	. . 3 ⊢ ((𝐾 ∈ DivRingOps ∧ 𝐾 ∈ Com2) → 𝐾 ∈ Fld)
10	5, 9	sylan2 605	. 2 ⊢ ((𝐾 ∈ DivRingOps ∧ 𝐾 ∈ CRingOps) → 𝐾 ∈ Fld)
11	3, 10	impbii 212	1 ⊢ (𝐾 ∈ Fld ↔ (𝐾 ∈ DivRingOps ∧ 𝐾 ∈ CRingOps))

This proof depends on syntax axioms:   ↔ wb 209   ∧ wa 401   ∈ wcel 2145   ∩ cin 3898  RingOpscrngo 38644  DivRingOpscdrng 38698  Com2ccm2 38739  Fldcfld 38741  CRingOpsccring 38743

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-8 2147  ax-9 2155  ax-10 2178  ax-11 2194  ax-12 2213  ax-ext 2732  ax-sep 5251  ax-nul 5263  ax-pr 5398  ax-un 7736

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3an 1105  df-tru 1573  df-fal 1583  df-ex 1813  df-nf 1817  df-sb 2100  df-mo 2564  df-eu 2594  df-clab 2739  df-cleq 2752  df-clel 2835  df-nfc 2909  df-ne 2956  df-ral 3077  df-rex 3087  df-rab 3413  df-v 3452  df-dif 3902  df-un 3904  df-in 3906  df-ss 3916  df-nul 4280  df-if 4483  df-sn 4585  df-pr 4587  df-op 4591  df-uni 4868  df-br 5104  df-opab 5168  df-mpt 5187  df-id 5550  df-xp 5661  df-rel 5662  df-cnv 5663  df-co 5664  df-dm 5665  df-rn 5666  df-res 5667  df-iota 6489  df-fun 6535  df-fv 6541  df-1st 7986  df-2nd 7987  df-drngo 38699  df-fld 38742  df-crngo 38744

This theorem is used by:  flddmn  38808  isfldidl  38818