∀[r:CRng]. IsIntegDom(r) supposing IsField(r)
{ Unfolds ``field_p integ_dom_p`` 0
THEN Auto⋅⋅ }
1. r : CRng
2. 0 ≠ 1 ∈ |r|
3. ∀u:|r|. (u ≠ 0 ∈ |r|
⇒ u | 1 in r)
4. 0 ≠ 1 ∈ |r|
5. u : |r|
6. v : |r|
7. ¬(v = 0 ∈ |r|)
8. (u * v) = 0 ∈ |r|
⊢ u = 0 ∈ |r|