=====Vector spaces over a field===== Abbreviation: **FVec** ====Definition==== A \emph{vector space over a [[fields]]} $\mathbf{F}$ is a structure $\mathbf{V}=\langle V,+,-,0,f_a\ (a\in F)\rangle$ such that $\langle V,+,-,0\rangle $ is an [[abelian groups]] scalar product $f_a$ distributes over vector addition: $a(x+y)=ax+ay$ $f_{1}$ is the identity map: $1x=x$ scalar product distributes over scalar addition: $(a+b)x=ax+bx$ scalar product associates: $(a\cdot b)x=a(bx)$ Remark: $f_a(x)=ax$ is called \emph{scalar multiplication by $a$}. ==Morphisms== Let $\mathbf{V}$ and $\mathbf{W}$ be vector spaces over a field $\mathbf{F}$. A morphism from $\mathbf{V}$ to $\mathbf{W}$ is a function $h:V\rightarrow W$ that is \emph{linear}: $h(x+y)=h(x)+h(y)$, $h(ax)=ah(x)$ for all $a\in F$ ====Examples==== Example 1: ====Basic results==== ====Properties==== ^[[Classtype]] |variety | ^[[Equational theory]] | | ^[[Quasiequational theory]] | | ^[[First-order theory]] | | ^[[Locally finite]] |no | ^[[Residual size]] |unbounded | ^[[Congruence distributive]] |no | ^[[Congruence modular]] |yes | ^[[Congruence n-permutable]] |yes, $n=2$ | ^[[Congruence regular]] |yes | ^[[Congruence uniform]] |yes | ^[[Congruence extension property]] |yes | ^[[Definable principal congruences]] |no | ^[[Equationally def. pr. cong.]] |no | ^[[Amalgamation property]] | | ^[[Strong amalgamation property]] | | ^[[Epimorphisms are surjective]] | | ====Finite members==== $\begin{array}{lr} f(1)= &1\\ f(2)= &\\ f(3)= &\\ f(4)= &\\ f(5)= &\\ f(6)= &\\ \end{array}$ ====Subclasses==== ====Superclasses==== [[Abelian groups]] ====References==== [(Ln19xx> )]