left / right perpendicular
Given a sesquilinear form over the field , if such that then we say is right perpendicular to and denote it . Likewise is left perpendicular to and can be denoted by .
By definition if and only if . However, need not imply .
For example, let and . Then so , or equivalently, .However so is not right perpendicular to and is not left perpendicular to .