Abbreviation: GödA
A \emph{Gödel algebra} is a Heyting algebras A=⟨A,∨,0,∧,1,→⟩ such that
(x→y)∨(y→x)=1
Remark: Gödel algebras are also called \emph{linear Heyting algebras} since subdirectly irreducible Gödel algebras are linearly ordered Heyting algebras.
A \emph{Gödel algebra} is a representable FLew-algebra A=⟨A,∨,0,∧,1,⋅,→⟩ such that
x∧y=x⋅y
Let A and B be Gödel algebras. A morphism from A to B is a function h:A→B that is a homomorphism:
h(x∨y)=h(x)∨h(y), h(0)=0, h(x∧y)=h(x)∧h(y), h(1)=1, h(x→y)=h(x)→h(y)
Example 1:
Classtype | variety |
---|---|
Equational theory | decidable |
Quasiequational theory | decidable |
First-order theory | |
Locally finite | |
Residual size | countable |
Congruence distributive | yes |
Congruence modular | yes |
Congruence n-permutable | yes, n=2 |
Congruence e-regular | yes, e=1 |
Congruence uniform | |
Congruence extension property | yes |
Definable principal congruences | yes |
Equationally def. pr. cong. | yes |
Amalgamation property | |
Strong amalgamation property | |
Epimorphisms are surjective |
f(1)=1f(2)=1f(3)=1f(4)=2f(5)=1f(6)=2f(7)=1f(8)=3f(9)=1f(10)=2