=====Generalized effect algebras===== Abbreviation: **GEAlg** ====Definition==== A \emph{generalized effect algebra} is a [[separation algebra]] that is \emph{positive}: $x\cdot y=e$ implies $x=e=y$. ====Definition==== A \emph{generalized effect algebra} is of the form $\langle A,+,0\rangle$ where $+:A^2\to A\cup\{*\}$ is a partial operation such that $+$ is \emph{commutative}: $x+y\ne *$ implies $x+y=y+x$ $+$ is \emph{associative}: $x+y\ne *$ implies $(x+y)+z=x+(y+z)$ $0$ is an \emph{identity}: $x+0=x$ $+$ is \emph{cancellative}: $x+y=x+z$ implies $y=z$ and $+$ is \emph{positive}: $x+y=0$ implies $x=0$. ==Morphisms== Let $\mathbf{A}$ and $\mathbf{B}$ be generalized effect algebra. A morphism from $\mathbf{A}$ to $\mathbf{B}$ is a function $h:A\rightarrow B$ that is a homomorphism: $h(e)=e$ and if $x + y\ne *$ then $h(x + y)=h(x) + h(y)$. ====Examples==== Example 1: ====Basic results==== ====Properties==== ^[[Classtype]] |first-order | ^[[Equational theory]] | | ^[[Quasiequational theory]] | | ^[[First-order theory]] | | ^[[Locally finite]] | | ^[[Residual size]] | | ^[[Congruence distributive]] | | ^[[Congruence modular]] | | ^[[Congruence $n$-permutable]] | | ^[[Congruence regular]] | | ^[[Congruence uniform]] | | ^[[Congruence extension property]] | | ^[[Definable principal congruences]] | | ^[[Equationally def. pr. cong.]] | | ^[[Amalgamation property]] | | ^[[Strong amalgamation property]] | | ^[[Epimorphisms are surjective]] | | ====Finite members==== $\begin{array}{lr} f(1)= &1\\ f(2)= &1\\ f(3)= &2\\ f(4)= &5\\ f(5)= &12\\ f(6)= &35\\ f(7)= &119\\ f(8)= &496\\ f(9)= &2699\\ f(10)= &21888\\ f(11)= &292496\\ \end{array}$ ====Subclasses==== [[Effect algebras]] [[Generalized orthoalgebras]] ====Superclasses==== [[separation algebras]] [[Generalized pseudo-effect algebras]] ====References====