- fl=? x y z ...procedure
- fl<? x y z ...procedure
- fl>? x y z ...procedure
- fl<=? x y z ...procedure
- fl>=? x y z ...procedure
These procedures return #t if their arguments are (respectively): equal, monotonically increasing, monotonically decreasing, monotonically nondecreasing, or monotonically nonincreasing; they return #f otherwise. These predicates must be transitive. (C99 =, <, >, <=, >= operators respectively)