=====Cancellative partial monoids===== Abbreviation: **CanPMon** ====Definition==== A \emph{cancellative partial monoid} is a [[partial monoid]] such that $\cdot$ is \emph{left-cancellative}: $x\cdot y=x\cdot z\ne *$ implies $y=z$ and $\cdot$ is \emph{right-cancellative}: $x\cdot z=y\cdot z\ne *$ implies $x=y$. ==Morphisms== Let $\mathbf{A}$ and $\mathbf{B}$ be cancellative partial monoids. A morphism from $\mathbf{A}$ to $\mathbf{B}$ is a function $h:A\rightarrow B$ that is a homomorphism: $h(e)=e$ and if $x\cdot y\ne *$ then $h(x \cdot y)=h(x) \cdot h(y)$. ====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==== See http://mathv.chapman.edu/~jipsen/uajs/CanPMon.html $\begin{array}{lr} f(1)= &1\\ f(2)= &2\\ f(3)= &3\\ f(4)= &9\\ f(5)= &21\\ f(6)= &125\\ f(7)= &\\ f(8)= &\\ f(9)= &\\ f(10)= &\\ \end{array}$ ====Subclasses==== [[Cancellative commutative partial monoids]] [[Cancellative monoids]] ====Superclasses==== [[Partial monoids]] ====References====