A = 
[[1,3,5,7,9]
 [2,4,6,8,10]
 [3,5,7,9,11]
 [4,6,8,10,12]
 [5,7,9,11,13]]

A(R,R) = 
[[4,6]
 [5,7]]

 MC(R) = [1,1]

 MB = [10,12] = [0,10,12,0,0]

testing infix

A = 
[[4,6]
 [5,7]]

 MC = [1,1,1,1,1]

 MB(R) += A(R,R) * MC(R) = [0,20,24,0,0]

 explicit blas call

 MC = [1,1,1,1,1]

A = 
[[4,6]
 [5,7]]

 MB = [0,10,12,0,0]

A = 
[[4,6]
 [5,7]]

 MB = [0,10,12,0,0]

A = 
[[4,5]
 [6,7]]

 MB = [0,9,13,0,0]