$ perl -le '$a = 36.8; $b = 36.6; print "true\n" if $a >= ($b + 0.2);' # Prints nothing, just as poster showed $ perl -le '$a = 36.8; $b = 36.6; $c = $b + 0.2; print $c;' 36.8 $ perl -le '$a = 36.8; $b = 36.6; $c = $b + 0.2; print $a;' 36.8 $ perl -le '$a = 36.8; $b = 36.6; $c = $b + 0.2; print $b;' 36.6