Here I document some of the more primitive relations, particularly those with names I use quite broadly, giving name (if any) and denotations which describe the relation.
r relates x to yimplies
s relates x to y:{relations})
which relates s to r precisely if s agrees with r about everything r says, optionally saying more.
r relates x to yiff
s relates y to x:{relations})
which interchanges the rôles of left
and right
. Transitive fixed points of reverse are described as equivalences.
Not to be confused with ...
which reverses
the order of entries in a list, in the sense
[z,…,a] ← [a,…,z]. I studiously do not call this
mapping reverse
, because I reserve that name for the mapping from
relations to relations given above.
Written by Eddy.