if used as numbers ( == > < + / * - ) strings are number (perl is perl)

yeah, see Re: Incrementing "Infinity" bug (numification, perlnumber, magic increment decrement), perlnumber, perldata, Infinity and Inf?, atoi, atof, strtod, Is this odd behavior a floating point problem?, What Every Programmer Should Know About Floating-Point Arithmetic or Why don’t my numbers add up?