my $operand  = '[a-zA-Z0-9_]+' ;
my $re = qr{
    \A              # Beginning of line
    \s*             # Optional whitespace
    ($operand)      # Capture(1) Alphanumeric LHS
    \s*             # Optional whitespace
    (               # Capture(2) either:
        [<>!]=      #   <=, >=, !=
    |
        [<>=]       #   <, >, =
    )
    \s*             # Optional whitespace
    ($operand)      # Capture(3) Alphanumeric LHS
}x;