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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 | )abbrev domain DPMM DirectProductMatrixModule
++ Author: Stephen M. Watt
++ Date Created: 1986
++ Date Last Updated: June 4, 1991
++ Description:
++ This constructor provides a direct product type with a
++ left matrix-module view.
DirectProductMatrixModule(n, R, M, S) : SIG == CODE where
n : PositiveInteger
R : Ring
RowCol ==> DirectProduct(n,R)
M : SquareMatrixCategory(n,R,RowCol,RowCol)
S : LeftModule(R)
SIG ==> Join(DirectProductCategory(n,S),LeftModule(R), LeftModule(M))
CODE ==> DirectProduct(n, S) add
Rep := Vector(S)
r:R * x:$ == [r*x.i for i in 1..n]
m:M * x:$ == [ +/[m(i,j)*x.j for j in 1..n] for i in 1..n]
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