— Function: band a b

Create a band, i.e., a representation for the interval of frequencies [a..b].

— Command: limit-< band u
— Command: limit-< band u w
— Command: limit-<= band u
— Command: limit-<= band u w

These commands establish a specification of the form H(f) <= u(f) in the band band. There is no difference between limit-< and limit-<=. The weight w is an optional function of the frequency f. The default weight is 1. If band is a number, it is converted internally into the band consisting of the single frequency band. If u is a number, it is converted internally into the constant function (lambda (f) u). A similar conversion applies to the weight.

— Command: limit-> band u
— Command: limit-> band u w
— Command: limit->= band u
— Command: limit->= band u w

These commands establish a specification of the form H(f) >= u(f) in the band band. The remaining parameters are as in the command limit-<.

— Command: limit-= band u
— Command: limit-= band u w

Shortcut for the sequence of commands (limit-< band u w) and (limit-> band u w).

— Command: upward band
— Command: downward band

These commands establish a specification of the form H'(f) >= u(f) and H'(f) <= u(f) (respectively) in the band band.

— Command: concave-up band
— Command: concave-down band

These commands establish a specification of the form H”(f) >= u(f) and H”(f) <= u(f) (respectively) in the band band.