i1 : pieri({3,1}, {1}, QQ[a,b,c])  removes the last box from row 1 of the partition {3,1}
o1 =  3a 0 b 0 c 0 0 0 0 0 0 0 0 0 0 
 0 3a 0 b 0 c 0 0 0 0 0 0 0 0 0 
 0 0 2a 0 0 0 2b 0 c 0 0 0 0 0 0 
 0 0 0 2a 0 0 0 2b 0 c 0 0 0 0 0 
 0 0 0 0 2a 0 0 0 b 0 2c 0 0 0 0 
 0 0 0 0 0 2a 0 0 0 b 0 2c 0 0 0 
 0 0 0 0 0 0 0 a 1/2a 0 0 0 3b c 0 
 0 0 0 0 0 0 0 0 0 a 2a 0 0 2b 2c 
8 15
o1 : Matrix (QQ[a..c]) < (QQ[a..c])
