I want to decompose Fourier-Motzkin algorithm for educational reasons. Suppose I have
z_1=solve(4*x_2<=100,x_2)[0][0]
z_2=solve(-35*x_2<=-3,x_2)[0][0]
z_3=solve(12*x_2 <= 72,x_2)[0][0]
z_4=solve(1-1*x_2 <= 40,x_2)[0][0]
show(z_1,", ",z_2,", ",z_3,", ",z_4)
How coud I select the z_i according to the inequality sign and construct 2 sets.
Your data give:
sage: z_1
x_2 <= 25
sage: z_2
x_2 >= (3/35)
You can look at the operator of the symbolic expression as follows:
sage: z_1.operator()
<built-in function le>
sage: z_2.operator()
<built-in function ge>
You can recognize which operator it is as follows:
sage: z_1.operator() is operator.le
True
sage: z_1.operator() is operator.ge
False
sage: z_2.operator() is operator.le
False
sage: z_2.operator() is operator.ge
True
le stands for "less or equal than" and ge stands for "greater or equal than".
Asked: 2020-09-14 05:56:52 +0100
Seen: 616 times
Last updated: Sep 14 '20
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