When both side partial:
1) R is 1:1 = 2 minimum
2) R is m:n = 3 minimum
3)R is 1:m = 2 minimum
4)R is m:1 = 2 minimum
5)total participation of A in R
1) R is 1:1 = 1 minimum
2)R is 1:m = 2 minimum
3)R is m:1 = 2 minimum
6)total participation of A and B both in R
1) R is 1:1 = 1 minimum
2)R is 1:m = 1 minimum
3)R is m:1 = 1 minimum