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Taylor expansion in SageMath returns error

Hi, I need to find the Taylor coefficient of order 7 in the variable "x4" of the following function:

var('x1 x2 x3 x4 w1 w2 w3 w4 w5 w5 w6');

g= 1/4((w1^2w3^2x1^4x2^6x3^8 + 2(w1^2w3^2x1^4x2^6 + w1^2w3x1^3x2^5)x3^7 + (w1^2w3^2x1^4x2^6 + 2w1^2w3x1^3x2^5 + 2w1^2x1^2x2^4)x3^6)x4^6 + 2((w1^2w3^2x1^4x2^6 + (w1^2w3^2x1^4 + (2w1^2w3 + w1w3^2)x1^3)x2^5)x3^7 + 2(w1^2w3^2x1^4x2^6 + (w1^2w3^2x1^4 + (3w1^2w3 + w1w3^2)x1^3)x2^5 + (w1^2w3x1^3 + (w1^2 + w1w3)x1^2)x2^4)x3^6 + (w1^2w3^2x1^4x2^6 + (w1^2w3^2x1^4 + (4w1^2w3 + w1w3^2)x1^3)x2^5 + 2(w1^2w3x1^3 + (2w1^2 + w1w3)x1^2)x2^4 + 2(w1^2x1^2 + w1x1)x2^3)x3^5)x4^5 + ((w1^2w3^2x1^4x2^6 + 2(w1^2w3^2x1^4 + (3w1^2w3 + 2w1w3^2)x1^3)x2^5 + (w1^2w3^2x1^4 + 2(3w1^2w3 + 2w1w3^2)x1^3 + 2(3w1^2 + 6w1w3 + w3^2)x1^2)x2^4)x3^6 + 2(w1^2w3^2x1^4x2^6 + (2w1^2w3^2x1^4 + (7w1^2w3 + 4w1w3^2)x1^3)x2^5 + (w1^2w3^2x1^4 + 4(2w1^2w3 + w1w3^2)x1^3 + (9w1^2 + 16w1w3 + 2w3^2)x1^2)x2^4 + (w1^2w3x1^3 + (3w1^2 + 4w1w3)x1^2 + 2(3w1 + w3)x1)x2^3)x3^5 + (w1^2w3^2x1^4x2^6 + 2(w1^2w3^2x1^4 + 2(2w1^2w3 + w1w3^2)x1^3)x2^5 + (w1^2w3^2x1^4 + 2(5w1^2w3 + 2w1w3^2)x1^3 + 2(7w1^2 + 10w1w3 + w3^2)x1^2)x2^4 + 2(w1^2w3x1^3 + (5w1^2 + 4w1w3)x1^2 + 2(5w1 + w3)x1)x2^3 + 2(w1^2x1^2 + 4w1x1 + 2)x2^2)x3^4)x4^4 + 2(((w1^2w3 + w1w3^2)x1^3x2^5 + (2(w1^2w3 + w1w3^2)x1^3 + (3w1^2 + 10w1w3 + 2w3^2)x1^2)x2^4 + ((w1^2w3 + w1w3^2)x1^3 + (3w1^2 + 10w1w3 + 2w3^2)x1^2 + 4(3w1 + 2w3)x1)x2^3)x3^5 + (2(w1^2w3 + w1w3^2)x1^3x2^5 + (4(w1^2w3 + w1w3^2)x1^3 + (7w1^2 + 22w1w3 + 4w3^2)x1^2)x2^4 + 2((w1^2w3 + w1w3^2)x1^3 + 2(2w1^2 + 6w1w3 + w3^2)x1^2 + (17w1 + 10w3)x1)x2^3 + ((w1^2 + 2w1w3)x1^2 + 2(5w1 + 2w3)x1 + 8)x2^2)x3^4 + ((w1^2w3 + w1w3^2)x1^3x2^5 + 2((w1^2w3 + w1w3^2)x1^3 + (2w1^2 + 6w1w3 + w3^2)x1^2)x2^4 + ((w1^2w3 + w1w3^2)x1^3 + (5w1^2 + 14w1w3 + 2w3^2)x1^2 + 12(2w1 + w3)x1)x2^3 + ((w1^2 + 2w1w3)x1^2 + 2(7w1 + 2w3)x1 + 12)x2^2 + 2(w1x1 + 2)x2)x3^3)x4^3 + 24(x2^2 + 2x2 + 1)x3^2 + 2(((w1^2 + 4w1w3 + w3^2)x1^2x2^4 + 2((w1^2 + 4w1w3 + w3^2)x1^2 + (8w1 + 7w3)x1)x2^3 + ((w1^2 + 4w1w3 + w3^2)x1^2 + 2(8w1 + 7w3)x1 + 20)x2^2)x3^4 + 2((w1^2 + 4w1w3 + w3^2)x1^2x2^4 + (2(w1^2 + 4w1w3 + w3^2)x1^2 + 3(6w1 + 5w3)x1)x2^3 + ((w1^2 + 4w1w3 + w3^2)x1^2 + 4(5w1 + 4w3)x1 + 27)x2^2 + ((2w1 + w3)x1 + 7)x2)x3^3 + ((w1^2 + 4w1w3 + w3^2)x1^2x2^4 + 2((w1^2 + 4w1w3 + w3^2)x1^2 + 2(5w1 + 4w3)x1)x2^3 + ((w1^2 + 4w1w3 + w3^2)x1^2 + 6(4w1 + 3w3)x1 + 36)x2^2 + 2((2w1 + w3)x1 + 9)x2 + 2)x3^2)x4^2 + 24x2^2 + 48(x2^2 + 2x2 + 1)x3 + 12(((w1 + w3)x1x2^3 + (2(w1 + w3)x1 + 5)x2^2 + ((w1 + w3)x1 + 5)x2)x3^3 + (2(w1 + w3)x1x2^3 + (4(w1 + w3)x1 + 11)x2^2 + 2((w1 + w3)x1 + 6)x2 + 1)x3^2 + ((w1 + w3)x1x2^3 + 2((w1 + w3)x1 + 3)x2^2 + ((w1 + w3)x1 + 7)x2 + 1)x3)x4 + 48x2 + 24)e^(-w2x1x2x3x4)/((x2^3x3^6e^(w5x1x2) + 3x2^3x3^5e^(w5x1x2) + 3x2^3x3^4e^(w5x1x2) + x2^3x3^3e^(w5x1x2))x4^3e^(w6x1x2x3) + 3((x2^3 + x2^2)x3^5e^(w5x1x2) + 3(x2^3 + x2^2)x3^4e^(w5x1x2) + 3(x2^3 + x2^2)x3^3e^(w5x1x2) + (x2^3 + x2^2)x3^2e^(w5x1x2))x4^2e^(w6x1x2x3) + 3((x2^3 + 2x2^2 + x2)x3^4e^(w5x1x2) + 3(x2^3 + 2x2^2 + x2)x3^3e^(w5x1x2) + 3(x2^3 + 2x2^2 + x2)x3^2e^(w5x1x2) + (x2^3 + 2x2^2 + x2)x3e^(w5x1x2))x4e^(w6x1x2x3) + ((x2^3 + 3x2^2 + 3x2 + 1)x3^3e^(w5x1x2) + 3(x2^3 + 3x2^2 + 3x2 + 1)x3^2e^(w5x1x2) + 3(x2^3 + 3x2^2 + 3x2 + 1)x3e^(w5x1x2) + (x2^3 + 3x2^2 + 3x2 + 1)e^(w5x1x2))e^(w6x1x2*x3))

For this we used the command:

taylor(g,x4,0,7)

Then, this return:

RuntimeError: ECL says: THROW: The catch RAT-ERR is undefined. During handling of the above exception, another exception occurred: ...... TypeError: ECL says: THROW: The catch RAT-ERR is undefined.

However, if I compute taylor(g,x4,0,3) returns its expansion without problems, but in order > 3, returns error.

Can anybody say me why don't returns its taylor expansion in order beyond 3?

Taylor expansion in SageMath returns error

Hi, I need to find the Taylor coefficient of order 7 in the variable "x4" of the following function:

var('x1 x2 x3 x4 w1 w2 w3 w4 w5 w5 w6'); w6'); g= 1/4((w1^2w3^2x1^4x2^6x3^8 + 2(w1^2w3^2x1^4x2^6 + w1^2w3x1^3x2^5)x3^7 + (w1^2w3^2x1^4x2^6 + 2w1^2w3x1^3x2^5 + 2w1^2x1^2x2^4)x3^6)x4^6 + 2((w1^2w3^2x1^4x2^6 + (w1^2w3^2x1^4 + (2w1^2w3 + w1w3^2)x1^3)x2^5)x3^7 + 2(w1^2w3^2x1^4x2^6 + (w1^2w3^2x1^4 + (3w1^2w3 + w1w3^2)x1^3)x2^5 + (w1^2w3x1^3 1/4*((w1^2*w3^2*x1^4*x2^6*x3^8 + 2*(w1^2*w3^2*x1^4*x2^6 + w1^2*w3*x1^3*x2^5)*x3^7 + (w1^2*w3^2*x1^4*x2^6 + 2*w1^2*w3*x1^3*x2^5 + 2*w1^2*x1^2*x2^4)*x3^6)*x4^6 + 2*((w1^2*w3^2*x1^4*x2^6 + (w1^2*w3^2*x1^4 + (2*w1^2*w3 + w1*w3^2)*x1^3)*x2^5)*x3^7 + 2*(w1^2*w3^2*x1^4*x2^6 + (w1^2*w3^2*x1^4 + (3*w1^2*w3 + w1*w3^2)*x1^3)*x2^5 + (w1^2*w3*x1^3 + (w1^2 + w1w3)x1^2)x2^4)x3^6 + (w1^2w3^2x1^4x2^6 + (w1^2w3^2x1^4 + (4w1^2w3 + w1w3^2)x1^3)x2^5 + 2(w1^2w3x1^3 + (2w1^2 + w1w3)x1^2)x2^4 + 2(w1^2x1^2 + w1x1)x2^3)x3^5)x4^5 + ((w1^2w3^2x1^4x2^6 + 2(w1^2w3^2x1^4 + (3w1^2w3 + 2w1w3^2)x1^3)x2^5 + (w1^2w3^2x1^4 + 2(3w1^2w3 + 2w1w3^2)x1^3 + 2(3w1^2 + 6w1w3 + w3^2)x1^2)x2^4)x3^6 + 2(w1^2w3^2x1^4x2^6 + (2w1^2w3^2x1^4 + (7w1^2w3 + 4w1w3^2)x1^3)x2^5 + (w1^2w3^2x1^4 + 4(2w1^2w3 + w1w3^2)x1^3 + (9w1^2 + 16w1w3 + 2w3^2)x1^2)x2^4 + (w1^2w3x1^3 + (3w1^2 + 4w1w3)x1^2 + 2(3w1 + w3)x1)x2^3)x3^5 + (w1^2w3^2x1^4x2^6 + 2(w1^2w3^2x1^4 + 2(2w1^2w3 + w1w3^2)x1^3)x2^5 + (w1^2w3^2x1^4 + 2(5w1^2w3 + 2w1w3^2)x1^3 + 2(7w1^2 + 10w1w3 + w3^2)x1^2)x2^4 + 2(w1^2w3x1^3 + (5w1^2 + 4w1w3)x1^2 + 2(5w1 + w3)x1)x2^3 + 2(w1^2x1^2 + 4w1x1 + 2)x2^2)x3^4)x4^4 + 2(((w1^2w3 + w1w3^2)x1^3x2^5 + (2(w1^2w3 + w1w3^2)x1^3 + (3w1^2 + 10w1w3 + 2w3^2)x1^2)x2^4 + ((w1^2w3 + w1w3^2)x1^3 + (3w1^2 + 10w1w3 + 2w3^2)x1^2 + 4(3w1 + 2w3)x1)x2^3)x3^5 + (2(w1^2w3 + w1w3^2)x1^3x2^5 + (4(w1^2w3 + w1w3^2)x1^3 + (7w1^2 + 22w1w3 + 4w3^2)x1^2)x2^4 + 2((w1^2w3 + w1w3^2)x1^3 + 2(2w1^2 + 6w1w3 + w3^2)x1^2 + (17w1 + 10w3)x1)x2^3 w1*w3)*x1^2)*x2^4)*x3^6 + (w1^2*w3^2*x1^4*x2^6 + (w1^2*w3^2*x1^4 + (4*w1^2*w3 + w1*w3^2)*x1^3)*x2^5 + 2*(w1^2*w3*x1^3 + (2*w1^2 + w1*w3)*x1^2)*x2^4 + 2*(w1^2*x1^2 + w1*x1)*x2^3)*x3^5)*x4^5 + ((w1^2*w3^2*x1^4*x2^6 + 2*(w1^2*w3^2*x1^4 + (3*w1^2*w3 + 2*w1*w3^2)*x1^3)*x2^5 + (w1^2*w3^2*x1^4 + 2*(3*w1^2*w3 + 2*w1*w3^2)*x1^3 + 2*(3*w1^2 + 6*w1*w3 + w3^2)*x1^2)*x2^4)*x3^6 + 2*(w1^2*w3^2*x1^4*x2^6 + (2*w1^2*w3^2*x1^4 + (7*w1^2*w3 + 4*w1*w3^2)*x1^3)*x2^5 + (w1^2*w3^2*x1^4 + 4*(2*w1^2*w3 + w1*w3^2)*x1^3 + (9*w1^2 + 16*w1*w3 + 2*w3^2)*x1^2)*x2^4 + (w1^2*w3*x1^3 + (3*w1^2 + 4*w1*w3)*x1^2 + 2*(3*w1 + w3)*x1)*x2^3)*x3^5 + (w1^2*w3^2*x1^4*x2^6 + 2*(w1^2*w3^2*x1^4 + 2*(2*w1^2*w3 + w1*w3^2)*x1^3)*x2^5 + (w1^2*w3^2*x1^4 + 2*(5*w1^2*w3 + 2*w1*w3^2)*x1^3 + 2*(7*w1^2 + 10*w1*w3 + w3^2)*x1^2)*x2^4 + 2*(w1^2*w3*x1^3 + (5*w1^2 + 4*w1*w3)*x1^2 + 2*(5*w1 + w3)*x1)*x2^3 + 2*(w1^2*x1^2 + 4*w1*x1 + 2)*x2^2)*x3^4)*x4^4 + 2*(((w1^2*w3 + w1*w3^2)*x1^3*x2^5 + (2*(w1^2*w3 + w1*w3^2)*x1^3 + (3*w1^2 + 10*w1*w3 + 2*w3^2)*x1^2)*x2^4 + ((w1^2*w3 + w1*w3^2)*x1^3 + (3*w1^2 + 10*w1*w3 + 2*w3^2)*x1^2 + 4*(3*w1 + 2*w3)*x1)*x2^3)*x3^5 + (2*(w1^2*w3 + w1*w3^2)*x1^3*x2^5 + (4*(w1^2*w3 + w1*w3^2)*x1^3 + (7*w1^2 + 22*w1*w3 + 4*w3^2)*x1^2)*x2^4 + 2*((w1^2*w3 + w1*w3^2)*x1^3 + 2*(2*w1^2 + 6*w1*w3 + w3^2)*x1^2 + (17*w1 + 10*w3)*x1)*x2^3 + ((w1^2 + 2w1w3)x1^2 + 2(5w1 + 2w3)x1 + 8)x2^2)x3^4 + ((w1^2w3 + w1w3^2)x1^3x2^5 + 2((w1^2w3 + w1w3^2)x1^3 + (2w1^2 + 6w1w3 + w3^2)x1^2)x2^4 + ((w1^2w3 + w1w3^2)x1^3 + (5w1^2 + 14w1w3 + 2w3^2)x1^2 + 12(2w1 + w3)x1)x2^3 2*w1*w3)*x1^2 + 2*(5*w1 + 2*w3)*x1 + 8)*x2^2)*x3^4 + ((w1^2*w3 + w1*w3^2)*x1^3*x2^5 + 2*((w1^2*w3 + w1*w3^2)*x1^3 + (2*w1^2 + 6*w1*w3 + w3^2)*x1^2)*x2^4 + ((w1^2*w3 + w1*w3^2)*x1^3 + (5*w1^2 + 14*w1*w3 + 2*w3^2)*x1^2 + 12*(2*w1 + w3)*x1)*x2^3 + ((w1^2 + 2w1w3)x1^2 + 2(7w1 + 2w3)x1 + 12)x2^2 + 2(w1x1 + 2)x2)x3^3)x4^3 + 24(x2^2 + 2x2 + 1)x3^2 + 2(((w1^2 + 4w1w3 + w3^2)x1^2x2^4 + 22*w1*w3)*x1^2 + 2*(7*w1 + 2*w3)*x1 + 12)*x2^2 + 2*(w1*x1 + 2)*x2)*x3^3)*x4^3 + 24*(x2^2 + 2*x2 + 1)*x3^2 + 2*(((w1^2 + 4*w1*w3 + w3^2)*x1^2*x2^4 + 2*((w1^2 + 4*w1*w3 + w3^2)*x1^2 + (8*w1 + 7*w3)*x1)*x2^3 + ((w1^2 + 4w1w3 + w3^2)x1^2 + (8w1 + 7w3)x1)x2^3 4*w1*w3 + w3^2)*x1^2 + 2*(8*w1 + 7*w3)*x1 + 20)*x2^2)*x3^4 + 2*((w1^2 + 4*w1*w3 + w3^2)*x1^2*x2^4 + (2*(w1^2 + 4*w1*w3 + w3^2)*x1^2 + 3*(6*w1 + 5*w3)*x1)*x2^3 + ((w1^2 + 4w1w3 + w3^2)x1^2 + 2(8w1 + 7w3)x1 + 20)x2^2)x3^4 + 24*w1*w3 + w3^2)*x1^2 + 4*(5*w1 + 4*w3)*x1 + 27)*x2^2 + ((2*w1 + w3)*x1 + 7)*x2)*x3^3 + ((w1^2 + 4w1w3 + w3^2)x1^2x2^4 + (2(w1^2 + 4w1w3 + w3^2)x1^2 + 3(6w1 + 5w3)x1)x2^3 4*w1*w3 + w3^2)*x1^2*x2^4 + 2*((w1^2 + 4*w1*w3 + w3^2)*x1^2 + 2*(5*w1 + 4*w3)*x1)*x2^3 + ((w1^2 + 4w1w3 + w3^2)x1^2 + 4(5w1 + 4w3)x1 + 27)x2^2 + ((2w1 + w3)x1 + 7)x2)x3^3 + ((w1^2 + 4w1w3 + w3^2)x1^2x2^4 + 2((w1^2 + 4w1w3 + w3^2)x1^2 + 2(5w1 + 4w3)x1)x2^3 + ((w1^2 + 4w1w3 + w3^2)x1^2 + 6(4w1 + 3w3)x1 + 36)x2^2 + 2((2w1 + w3)x1 + 9)x2 + 2)x3^2)x4^2 + 24x2^2 + 48(x2^2 + 2x2 + 1)x3 + 12(((w1 + w3)x1x2^3 + (2(w1 + w3)x1 + 5)x2^2 4*w1*w3 + w3^2)*x1^2 + 6*(4*w1 + 3*w3)*x1 + 36)*x2^2 + 2*((2*w1 + w3)*x1 + 9)*x2 + 2)*x3^2)*x4^2 + 24*x2^2 + 48*(x2^2 + 2*x2 + 1)*x3 + 12*(((w1 + w3)*x1*x2^3 + (2*(w1 + w3)*x1 + 5)*x2^2 + ((w1 + w3)x1 + 5)x2)x3^3 + (2(w1 + w3)x1x2^3 + (4(w1 + w3)x1 + 11)x2^2 + 2w3)*x1 + 5)*x2)*x3^3 + (2*(w1 + w3)*x1*x2^3 + (4*(w1 + w3)*x1 + 11)*x2^2 + 2*((w1 + w3)*x1 + 6)*x2 + 1)*x3^2 + ((w1 + w3)x1 + 6)x2 + 1)x3^2 w3)*x1*x2^3 + 2*((w1 + w3)*x1 + 3)*x2^2 + ((w1 + w3)x1x2^3 + 2((w1 + w3)x1 + 3)x2^2 + ((w1 + w3)x1 + 7)x2 + 1)x3)x4 + 48x2 + 24)e^(-w2x1x2x3x4)/((x2^3x3^6e^(w5x1x2) + 3x2^3x3^5e^(w5x1x2) + 3x2^3x3^4e^(w5x1x2) + x2^3x3^3e^(w5x1x2))x4^3e^(w6x1x2x3) + 3w3)*x1 + 7)*x2 + 1)*x3)*x4 + 48*x2 + 24)*e^(-w2*x1*x2*x3*x4)/((x2^3*x3^6*e^(w5*x1*x2) + 3*x2^3*x3^5*e^(w5*x1*x2) + 3*x2^3*x3^4*e^(w5*x1*x2) + x2^3*x3^3*e^(w5*x1*x2))*x4^3*e^(w6*x1*x2*x3) + 3*((x2^3 + x2^2)*x3^5*e^(w5*x1*x2) + 3*(x2^3 + x2^2)*x3^4*e^(w5*x1*x2) + 3*(x2^3 + x2^2)*x3^3*e^(w5*x1*x2) + (x2^3 + x2^2)*x3^2*e^(w5*x1*x2))*x4^2*e^(w6*x1*x2*x3) + 3*((x2^3 + 2*x2^2 + x2)*x3^4*e^(w5*x1*x2) + 3*(x2^3 + 2*x2^2 + x2)*x3^3*e^(w5*x1*x2) + 3*(x2^3 + 2*x2^2 + x2)*x3^2*e^(w5*x1*x2) + (x2^3 + 2*x2^2 + x2)*x3*e^(w5*x1*x2))*x4*e^(w6*x1*x2*x3) + ((x2^3 + x2^2)x3^5e^(w5x1x2) + 33*x2^2 + 3*x2 + 1)*x3^3*e^(w5*x1*x2) + 3*(x2^3 + 3*x2^2 + 3*x2 + 1)*x3^2*e^(w5*x1*x2) + 3*(x2^3 + 3*x2^2 + 3*x2 + 1)*x3*e^(w5*x1*x2) + (x2^3 + x2^2)x3^4e^(w5x1x2) + 3(x2^3 + x2^2)x3^3e^(w5x1x2) + (x2^3 + x2^2)x3^2e^(w5x1x2))x4^2e^(w6x1x2x3) + 3((x2^3 + 2x2^2 + x2)x3^4e^(w5x1x2) + 3(x2^3 + 2x2^2 + x2)x3^3e^(w5x1x2) + 3(x2^3 + 2x2^2 + x2)x3^2e^(w5x1x2) + (x2^3 + 2x2^2 + x2)x3e^(w5x1x2))x4e^(w6x1x2x3) + ((x2^3 + 3x2^2 + 3x2 + 1)x3^3e^(w5x1x2) + 3(x2^3 + 3x2^2 + 3x2 + 1)x3^2e^(w5x1x2) + 3(x2^3 + 3x2^2 + 3x2 + 1)x3e^(w5x1x2) + (x2^3 + 3x2^2 + 3x2 + 1)e^(w5x1x2))e^(w6x1x2*x3))3*x2^2 + 3*x2 + 1)*e^(w5*x1*x2))*e^(w6*x1*x2*x3))

For this we used the command:
~~taylor(g,x4,0,7)~~
taylor(g,x4,0,7)

Then, this return:

RuntimeError: ECL says: THROW: The catch RAT-ERR is undefined. During handling of the above exception, another exception occurred: ...... TypeError: ECL says: THROW: The catch RAT-ERR is undefined.
undefined.

However, if I compute taylor(g,x4,0,3) returns its expansion without problems, but in order > 3, returns error.

Can anybody say me why don't returns its taylor expansion in order beyond 3?