testing reduction and it seems to work!

Author: Transurgeon

cvxpy/atoms/atom.py

@@ -154,6 +154,9 @@ def is_atom_log_log_affine(self) -> bool:
         """
         return self.is_atom_log_log_concave() and self.is_atom_log_log_convex()
 
+    def is_atom_smooth(self) -> bool:
+        pass
+
     @abc.abstractmethod
     def is_incr(self, idx) -> bool:
         """Is the composition non-decreasing in argument idx?
@@ -212,6 +215,12 @@ def is_dpp(self, context='dcp') -> bool:
 
     def is_smooth(self) -> bool:
         "The expression is smooth"
+        if self.is_constant():
+            return True
+        elif self.is_smooth_atom(self):
+            for idx, arg in enumerate(self.args):
+                if not arg.is_smooth():
+                    return False
         return True
 
     @perf.compute_once

cvxpy/reductions/expr2smooth/canonicalizers/__init__.py

@@ -14,7 +14,7 @@
 limitations under the License.
 """
 from cvxpy.atoms import maximum
-from cvxpy.reductions.expr2smooth.canonicalizers import maximum_canon
+from cvxpy.reductions.expr2smooth.canonicalizers.maximum_canon import maximum_canon
 
 CANON_METHODS = {
     maximum : maximum_canon,

cvxpy/reductions/expr2smooth/expr2smooth.py

@@ -16,9 +16,9 @@
 
 from typing import Tuple
 
+import cvxpy as cp
 from cvxpy import problems
 from cvxpy.expressions.expression import Expression
-from cvxpy.problems.objective import Minimize
 from cvxpy.reductions.canonicalization import Canonicalization
 from cvxpy.reductions.expr2smooth.canonicalizers import CANON_METHODS as smooth_canon_methods
 from cvxpy.reductions.inverse_data import InverseData
@@ -36,8 +36,8 @@ def __init__(self, problem=None, quad_obj: bool = False) -> None:
         self.quad_obj = quad_obj
 
     def accepts(self, problem):
-        """A problem is accepted if it is a minimization."""
-        return type(problem.objective) == Minimize
+        """A problem is always accepted"""
+        return True
 
     def apply(self, problem):
         """Converts an expr to a smooth program"""
@@ -108,3 +108,19 @@ def canonicalize_expr(self, expr, args, affine_above: bool) -> Tuple[Expression,
             return self.smooth_canon_methods[type(expr)](expr, args)
 
         return expr.copy(args), []
+
+def example_max():
+    # Define variables
+    x = cp.Variable(1)
+    y = cp.Variable(1)
+    
+    objective = cp.Minimize(-cp.maximum(x,y))
+    
+    constraints = [x - 14 == 0, y - 6 == 0]
+    
+    problem = cp.Problem(objective, constraints)
+    return problem
+
+prob = example_max()
+new_problem, inverse = Expr2smooth(prob).apply(prob)
+print(new_problem)