These little functions are defined in package Poly. Due to the namespace import they are directly
available in all rulefiles and included perl modules.
return the list without duplicates; sorted variants are optimized for the assumption that the input is already
lexicographically or numerically sorted.
performs a binary search for $x in the list. Returns a boolean TRUE if found, FALSE otherwise.
The list is assumed increasingly sorted (decreasingly if $order==-1).
Display messages of the certain category. Currently everything goes to STDERR and is distiguished only by a prefix. This
may change with the further evolving of the interactive facilities in polymake.
make the given variable $x write-protected. An attempt to change its value raises an exception.
If is an array reference, each array element is made write-protected too.
remove the imported function pointed by the given glob. Unlike by undef &sub, it's only the reference from another
package's symbol table that gets destroyed, not the subroutine body.