% PostScript has 'sin' and 'cos', but not these
/asin { dup dup 1. add exch 1. exch sub mul sqrt atan } def
/acos { dup dup 1. add exch 1. exch sub mul sqrt exch atan } def

/cube { 3 exp } def
/cuberoot { 1. 3. div exp } def

/compose { % f g -> { g f }
  [ 3 1 roll exch
  % procedures are not executed when encountered directly
  % insert an 'exec' after procedures, but not after operators
  1 index type /operatortype ne { /exec cvx exch } if
  dup type /operatortype ne { /exec cvx } if
  ] cvx
} def

/funcs [ /sin load /cos load /cube load ] def
/ifuncs [ /asin load /acos load /cuberoot load ] def

0 1 funcs length 1 sub { /i exch def
  ifuncs i get funcs i get compose
  .5 exch exec ==
} for