i1 : betti res coker pureFree({0,1,2,4}, QQ[a,b,c])  degree sequence {0,1,2,4}
0 1 2 3
o1 = total: 3 8 6 1
0: 3 8 6 .
1: . . . 1
o1 : BettiTally

i2 : betti res coker pureFree({0,1,2,4}, ZZ/2[a,b,c])  same map, but reduced mod 2
0 1 2 3
o2 = total: 3 8 6 1
0: 3 8 6 .
1: . . . 1
o2 : BettiTally

i3 : betti res coker pureFree({0,1,2,4}, GF(4)[a,b,c])  can also use non prime fields
0 1 2 3
o3 = total: 3 8 6 1
0: 3 8 6 .
1: . . . 1
o3 : BettiTally
