### A good answer might be:

    if ( !( a < 0 ) ) { ... }

    if ( a >= 0  ) { ... }

The two operators `<` and `>=` cover all possible integer values.

# Set on Less Than

The set instructions are used to implement relational operators. However, they do not in themselves alter the flow of control. They set a register to 1 or 0 to show the relation between two values. The `slt` instruction is used with two's complement integers:

                       #  $s and $t contain
                       #  two's comp. integers
                       #
    slt   d,s,t        #  if ( $s < $t )
                       #    d <-- 1
                       #  else
                       #    d <-- 0

The `sltu` instruction is used with unsigned integers:

                       #  $s and $t contain
                       #  unsigned integers
                       #
    sltu  d,s,t        #  if ( $s < $t )
                       #    d <-- 1
                       #  else
                       #    d <-- 0

### QUESTION 3:

Could these instructions be used with character data?