remove takes as argument: a boolean function f and
a list L.
remove removes in the list L, the elements c such that
f(c)==true.
Input:
Output:
Remark The same applies on strings, for example,
to remove all the "a" of a string:
Input:
Output:
Input:
f(chn):={ local l:=length(chn)-1; return remove(x->(ord(x)==97),seq(chn[k],k,0,l)); }
Then, input:
Output:
To get a string, input:
Output: