CVXPY
Maximize
  Sum(x, None, False)
Subject To
 19: reshape(x, (2, 2), F) <= [[1.00 1.00]
 [1.00 1.00]]
Bounds
 x free
End
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AFTER COMPILATION
Minimize
  - C0 - C1 - C2 - C3
Subject To
 R0: C0 <= 1
 R1: C1 <= 1
 R2: C2 <= 1
 R3: C3 <= 1
Bounds
 C0 free
 C1 free
 C2 free
 C3 free
End
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GUROBI
Maximize
  x[0] + x[1] + x[2] + x[3]
Subject To
 19[0,0]: x[0] <= 1
 19[0,1]: x[1] <= 1
 19[1,0]: x[2] <= 1
 19[1,1]: x[3] <= 1
Bounds
 x[0] free
 x[1] free
 x[2] free
 x[3] free
End