GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it
1[1X1 [33X[0;0YCategory of Matrices[133X[101X234[1X1.1 [33X[0;0YConstructors[133X[101X56[1X1.1-1 MatrixCategory[101X78[29X[2XMatrixCategory[102X( [3XF[103X ) [32X attribute9[6XReturns:[106X [33X[0;10Ya category[133X1011[33X[0;0YThe argument is a homalg field [23XF[123X. The output is the matrix category over [23XF[123X.12Objects in this category are non-negative integers. Morphisms from a13non-negative integer [23Xm[123X to a non-negative integer [23Xn[123X are given by [23Xm \times n[123X14matrices.[133X1516[1X1.1-2 VectorSpaceMorphism[101X1718[29X[2XVectorSpaceMorphism[102X( [3XS[103X, [3XM[103X, [3XR[103X ) [32X operation19[6XReturns:[106X [33X[0;10Ya morphism in [23X\mathrm{Hom}(S,R)[123X[133X2021[33X[0;0YThe arguments are an object [23XS[123X in the category of matrices over a homalg22field [23XF[123X, a homalg matrix [23XM[123X over [23XF[123X, and another object [23XR[123X in the category of23matrices over [23XF[123X. The output is the morphism [23XS \rightarrow R[123X in the category24of matrices over [23XF[123X whose underlying matrix is given by [23XM[123X.[133X2526[1X1.1-3 VectorSpaceObject[101X2728[29X[2XVectorSpaceObject[102X( [3Xd[103X, [3XF[103X ) [32X operation29[6XReturns:[106X [33X[0;10Yan object[133X3031[33X[0;0YThe arguments are a non-negative integer [23Xd[123X and a homalg field [23XF[123X. The output32is an object in the category of matrices over [23XF[123X of dimension [23Xd[123X.[133X333435[1X1.2 [33X[0;0YGAP Categories[133X[101X3637[1X1.2-1 IsVectorSpaceMorphism[101X3839[29X[2XIsVectorSpaceMorphism[102X( [3Xobject[103X ) [32X filter40[6XReturns:[106X [33X[0;10Y[10Xtrue[110X or [10Xfalse[110X[133X4142[33X[0;0YThe GAP category of morphisms in the category of matrices of a field [23XF[123X.[133X4344[1X1.2-2 IsVectorSpaceObject[101X4546[29X[2XIsVectorSpaceObject[102X( [3Xobject[103X ) [32X filter47[6XReturns:[106X [33X[0;10Y[10Xtrue[110X or [10Xfalse[110X[133X4849[33X[0;0YThe GAP category of objects in the category of matrices of a field [23XF[123X.[133X505152[1X1.3 [33X[0;0YAttributes[133X[101X5354[1X1.3-1 UnderlyingFieldForHomalg[101X5556[29X[2XUnderlyingFieldForHomalg[102X( [3Xalpha[103X ) [32X attribute57[6XReturns:[106X [33X[0;10Ya homalg field[133X5859[33X[0;0YThe argument is a morphism [23X\alpha[123X in the matrix category over a homalg field60[23XF[123X. The output is the field [23XF[123X.[133X6162[1X1.3-2 UnderlyingMatrix[101X6364[29X[2XUnderlyingMatrix[102X( [3Xalpha[103X ) [32X attribute65[6XReturns:[106X [33X[0;10Ya homalg matrix[133X6667[33X[0;0YThe argument is a morphism [23X\alpha[123X in a matrix category. The output is its68underlying matrix [23XM[123X.[133X6970[1X1.3-3 UnderlyingFieldForHomalg[101X7172[29X[2XUnderlyingFieldForHomalg[102X( [3XA[103X ) [32X attribute73[6XReturns:[106X [33X[0;10Ya homalg field[133X7475[33X[0;0YThe argument is an object [23XA[123X in the matrix category over a homalg field [23XF[123X.76The output is the field [23XF[123X.[133X7778[1X1.3-4 Dimension[101X7980[29X[2XDimension[102X( [3XA[103X ) [32X attribute81[6XReturns:[106X [33X[0;10Ya non-negative integer[133X8283[33X[0;0YThe argument is an object [23XA[123X in a matrix category. The output is the84dimension of [23XA[123X.[133X85868788