%!PS

/getdictstack {
    countdictstack array dictstack
    3 1 index length 3 sub
    getinterval
} bind def

/setdictstack {
    cleardictstack { begin } forall
} bind def

/fun-body { % <env> <proc>
    exch
    1 dict
    dup /oldenv getdictstack put
    exch setdictstack begin
    exec
    oldenv setdictstack
} bind def

[ getdictstack {/n exch def /n load 2 le {1} {/n load 1 sub fib /n load 2 sub fib add} ifelse} /fun-body cvx ] cvx /fib exch def

% Hayley's fib:
%
% /fib { dup 2 ge { dup -1 add fib exch -2 add fib add } if } bind def

100 { 25 fib pop } repeat

quit