involution
function that is its own inverse
logical negation
operation that takes a proposition p to another proposition "not p", written ¬p, which is interpreted intuitively as being true when p is false, and false when p is true; unary (single-argument) logical connective
symmetry
geometrical property and transformation
opposite number
number that, when added to the original number, yields zero
bit-reversal permutation
permutation that reverses binary numbers
permutation involution
permutation that is its own inverse
Affine involution
linear or affine transformation which is its own inverse
reciprocal function
function mapping a number to its reciprocal
identity function
function that always returns the same value that was used as its argument
complement graph
graph with same nodes but opposite connections as another