−Table of Contents
Action lattices
Abbreviation: ActLat
Definition
An \emph{action lattice} is a structure A=⟨A,∨,∧,0,⋅,1,∗,∖,/⟩ of type ⟨2,2,0,2,0,1,2,2⟩ such that
⟨A,∨,0,⋅,1,∗⟩ is a Kleene algebra
⟨A,∨,∧⟩ is a lattice
∖ is the left residual of ⋅: y≤x∖z⟺xy≤z
/ is the right residual of ⋅: x≤z/y⟺xy≤z
Morphisms
Let A and B be action lattices. A morphism from A to B is a function h:A→B that is a homomorphism:
h(x∨y)=h(x)∨h(y), h(x∧y)=h(x)∧h(y), h(x⋅y)=h(x)⋅h(y), h(x∖y)=h(x)∖h(y), h(x/y)=h(x)/h(y), h(x∗)=h(x)∗, h(0)=0, h(1)=1
Examples
Example 1:
Basic results
Properties
Classtype | variety |
---|---|
Equational theory | |
Quasiequational theory | undecidable |
First-order theory | undecidable |
Locally finite | no |
Residual size | unbounded |
Congruence distributive | yes |
Congruence modular | yes |
Congruence n-permutable | yes, n=2 |
Congruence regular | no |
Congruence e-regular | yes |
Congruence uniform | no |
Congruence extension property | no |
Definable principal congruences | no |
Equationally def. pr. cong. | no |
Amalgamation property | |
Strong amalgamation property | |
Epimorphisms are surjective |
Finite members
f(1)=1f(2)=1f(3)=3f(4)=20f(5)=149f(6)=1488