Example of the formula for coefficients of the non-square-free terms of a linear stress polynomial.

> with(linalg):

The simplicial complex has facets: 213, 143, 423, 125, 245, 415. Bipyramid over triangle 124.

The following are chosen for the coordinates of the vertices.

> v1:=[0,0,-1]; v2:=[2,0,1]; v3:=[0,1/2,1/2]; v4:=[-2,0,1]; v5:=[0,-1/2,1/2];

v1 := [0, 0, -1]

v2 := [2, 0, 1]

v3 := [0, 1/2, 1/2]

v4 := [-2, 0, 1]

v5 := [0, -1/2, 1/2]

> M:=transpose(array([v1,v2,v3,v4,v5]));

M := matrix([[0, 2, 0, -2, 0], [0, 0, 1/2, 0, -1/2]...

The following is a linear 3-stress.

> b3:=expand((1/24)*(2*x1+x2+x4)^2*(4*x1+6*x5-x2+6*x3-x4));

b3 := 2/3*x1^3+1/2*x2*x4*x3+1/2*x2*x4*x5+x1*x4*x3+x...
b3 := 2/3*x1^3+1/2*x2*x4*x3+1/2*x2*x4*x5+x1*x4*x3+x...

> u3:=[a,b,c];

u3 := [a, b, c]

> M1:=transpose(array([v1,v2,v3,v4,v5,u3]));

M1 := matrix([[0, 2, 0, -2, 0, a], [0, 0, 1/2, 0, -...

> b213:=1; b143:=1; b423:=1/2; b125:=1; b245:=1/2; b415:=1;

b213 := 1

b143 := 1

b423 := 1/2

b125 := 1

b245 := 1/2

b415 := 1

Calculate b115 (which should equal 2). r:=[2,0,0,0,1]. F125:=125. F415:=415.

> F1251:=(-det(submatrix(M1,[1,2,3],[2,5,6])))^1;

F1251 := c+b-1/2*a

> F1252:=(det(submatrix(M1,[1,2,3],[1,5,6])))^(-1);

F1252 := -2*1/a

> F1255:=(-det(submatrix(M1,[1,2,3],[1,2,6])))^0;

F1255 := 1

> F4154:=(-det(submatrix(M1,[1,2,3],[1,5,6])))^(-1);

F4154 := 2*1/a

> F4151:=(det(submatrix(M1,[1,2,3],[4,5,6])))^1;

F4151 := c+b+1/2*a

> F4155:=(-det(submatrix(M1,[1,2,3],[4,1,6])))^0;

F4155 := 1

> b115:=b125*F1251*F1252*F1255+b415*F4154*F4151*F4155;

b115 := -2*(c+b-1/2*a)/a+2/a*(c+b+1/2*a)

> expand(%);

2

Calculate b111 (which should equal 4). r:=[3,0,0,0,0]. F125:=125. F415:=415. F213:=213. F143:=143.

> F1251:=(-det(submatrix(M1,[1,2,3],[2,5,6])))^2;

F1251 := (-c-b+1/2*a)^2

> F1252:=(det(submatrix(M1,[1,2,3],[1,5,6])))^(-1);

F1252 := -2*1/a

> F1255:=(-det(submatrix(M1,[1,2,3],[1,2,6])))^(-1);

F1255 := 1/2*1/b

> F4154:=(-det(submatrix(M1,[1,2,3],[1,5,6])))^(-1);

F4154 := 2*1/a

> F4151:=(det(submatrix(M1,[1,2,3],[4,5,6])))^2;

F4151 := (c+b+1/2*a)^2

> F4155:=(-det(submatrix(M1,[1,2,3],[4,1,6])))^(-1);

F4155 := 1/2*1/b

> F2132:=(-det(submatrix(M1,[1,2,3],[1,3,6])))^(-1);

F2132 := -2*1/a

> F2131:=(det(submatrix(M1,[1,2,3],[2,3,6])))^2;

F2131 := (c-b-1/2*a)^2

> F2133:=(-det(submatrix(M1,[1,2,3],[2,1,6])))^(-1);

F2133 := -1/2*1/b

> F1431:=(-det(submatrix(M1,[1,2,3],[4,3,6])))^2;

F1431 := (-c+b-1/2*a)^2

> F1434:=(det(submatrix(M1,[1,2,3],[1,3,6])))^(-1);

F1434 := 2*1/a

> F1433:=(-det(submatrix(M1,[1,2,3],[1,4,6])))^(-1);

F1433 := -1/2*1/b

> b111:=b125*F1251*F1252*F1255+ b415*F4154*F4151*F4155+ b213*F2132*F2131*F2133+ b143*F1431*F1434*F1433;

b111 := -(-c-b+1/2*a)^2/a/b+1/a*(c+b+1/2*a)^2/b+1/a...

> expand(%);

4

>