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docs/customization.md

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+# Customization
+
+
+### Selecting the internal MIP solver
+
+By default, `LearningSolver` uses [Gurobi](https://www.gurobi.com/) as its internal MIP solver. Alternative solvers can be specified through the `internal_solver_factory` constructor argument. This argument should provide a function (with no arguments) that constructs, configures and returns the desired solver. To select CPLEX, for example:
+```python
+from miplearn import LearningSolver
+import pyomo.environ as pe
+
+def cplex_factory():
+    cplex = pe.SolverFactory("cplex")
+    cplex.options["threads"] = 4
+    return cplex
+
+solver = LearningSolver(internal_solver_factory=cplex_factory)
+```