ADDI r31, r0, n   ; r31 is 4 less than first address holding data
        LW   r1, 4(r31)   ; load into r1 the number we would like to test (n)
        SLTI r4, r1, #2   ; if the number is less than 2, without going further
        BNEZ r4, notprm   ;   we say it is not prime
        ADDI r2, r0, #2   ; let r2 be the divisor we would like to test (i)
nexti:  MULT r3, r2, r2   ; let r3 be i squared
        SGT  r4, r3, r1   ; if this is greater than n, then we can stop
        BNEZ r4, notprm   ;   since we know n is not prime
        MOD  r3, r1, r2   ; let r3 be the remainder of n divided by i
        BNEZ r3, nexti    ; if it is not zero, go to the next i
        ADDI r2, r2, #1   ; but we add one to i first (the delay slot)
isprm:  SW   8(r31), r0   ; n is  prime; store 0 in memory
        TRAP #0           ; end the program
notprm: SW   8(r31), r4   ; n is not prime; store 1 in memory
        TRAP #0           ; end the program
data:   .word 131         ; the number n to be tested
        .word -1          ; will be 0 if n is not prime, 1 if it is