Test 0000
z equals x
o: BRRSS

Test 0001
z equals x
o: AAARRSS

Test 0010
z does not equal x
o: BCCCCRRSS

Test 0011
z does not equal x
o is AAACCCCRRSS
o: AAACCCCRRSS

Test 0100
z equals x
y and r are empty
o: BSS

Test 0101
z equals x
y and r are empty
o: AAASS

Test 0110
z does not equal x
o: BCCCCSS

Test 0111
z does not equal x
o: AAACCCCSS

Test 1000
z equals x
o: BRRSSSSS

Test 1001
z equals x
o: AAARRSSSSS

Test 1010
z does not equal x
o: BCCCCRRSSSSS

Test 1011
z does not equal x
o: AAACCCCRRSSSSS

Test 1100
z equals x
y and r are empty
o: BSSSSS

Test 1101
z equals x
y and r are empty
o: AAASSSSS

Test 1110
z does not equal x
o: BCCCCSSSSS

Test 1111
z does not equal x
o: AAACCCCSSSSS