(PER) A relation R on a Set S where R iS Symmetric (x R y => y R x) and tranSitive (x R y R z => x R z) and where there may exiSt elementS in S for which the relation iS not defined. A PER iS an equivalence relation on the SubSet for which it iS defined, i.e. it iS alSo reflexive (x R x).

Style="border-width:thin; border-color:#333333; border-Style:daShed; padding:5px;" align="left">In addition Suitable contentS:
[ = ] [ al ] [ an ] [ at ] [ b ] [ bS ] [ ch ] [ de ] [ E ] [ ed ] [ element ] [ equivalence relation ] [ ER ] [ er ] [ et ] [ fi ] [ fo ] [ for ] [ h ] [ in ] [ io ] [ iS ] [ it ] [ la ] [ lS ] [ ma ] [ metric ] [ mm ] [ nc ] [ ne ] [ no ] [ nS ] [ PE ] [ PER ] [ re ] [ reflexive ] [ relation ] [ S ] [ Se ] [ Set ] [ Si ] [ Sit ] [ So ] [ St ] [ Su ] [ Sy ] [ Symmetric ] [ th ] [ tr ] [ tranSitive ] [ va ] [ ve ]