Metamath Proof Explorer


Definition df-ufd

Description: Define the class of unique factorization domains. A unique factorization domain (UFD for short), is a commutative ring with an absolute value (from abvtriv this is equivalent to being a domain) such that every prime ideal contains a prime element (this is a characterization due to Irving Kaplansky). A UFD is sometimes also called a "factorial ring" following the terminology of Bourbaki. (Contributed by Mario Carneiro, 17-Feb-2015)

Ref Expression
Assertion df-ufd UFD = { 𝑟 ∈ CRing ∣ ( ( AbsVal ‘ 𝑟 ) ≠ ∅ ∧ ∀ 𝑖 ∈ ( PrmIdeal ‘ 𝑟 ) ( 𝑖 ∩ ( RPrime ‘ 𝑟 ) ) ≠ ∅ ) }

Detailed syntax breakdown

Step Hyp Ref Expression
0 cufd UFD
1 vr 𝑟
2 ccrg CRing
3 cabv AbsVal
4 1 cv 𝑟
5 4 3 cfv ( AbsVal ‘ 𝑟 )
6 c0
7 5 6 wne ( AbsVal ‘ 𝑟 ) ≠ ∅
8 vi 𝑖
9 cprmidl PrmIdeal
10 4 9 cfv ( PrmIdeal ‘ 𝑟 )
11 8 cv 𝑖
12 crpm RPrime
13 4 12 cfv ( RPrime ‘ 𝑟 )
14 11 13 cin ( 𝑖 ∩ ( RPrime ‘ 𝑟 ) )
15 14 6 wne ( 𝑖 ∩ ( RPrime ‘ 𝑟 ) ) ≠ ∅
16 15 8 10 wral 𝑖 ∈ ( PrmIdeal ‘ 𝑟 ) ( 𝑖 ∩ ( RPrime ‘ 𝑟 ) ) ≠ ∅
17 7 16 wa ( ( AbsVal ‘ 𝑟 ) ≠ ∅ ∧ ∀ 𝑖 ∈ ( PrmIdeal ‘ 𝑟 ) ( 𝑖 ∩ ( RPrime ‘ 𝑟 ) ) ≠ ∅ )
18 17 1 2 crab { 𝑟 ∈ CRing ∣ ( ( AbsVal ‘ 𝑟 ) ≠ ∅ ∧ ∀ 𝑖 ∈ ( PrmIdeal ‘ 𝑟 ) ( 𝑖 ∩ ( RPrime ‘ 𝑟 ) ) ≠ ∅ ) }
19 0 18 wceq UFD = { 𝑟 ∈ CRing ∣ ( ( AbsVal ‘ 𝑟 ) ≠ ∅ ∧ ∀ 𝑖 ∈ ( PrmIdeal ‘ 𝑟 ) ( 𝑖 ∩ ( RPrime ‘ 𝑟 ) ) ≠ ∅ ) }