diff --git a/examples/tests/SatSolverTests.cs b/examples/tests/SatSolverTests.cs
index bbc8908960..4222cfdc1b 100644
--- a/examples/tests/SatSolverTests.cs
+++ b/examples/tests/SatSolverTests.cs
@@ -431,6 +431,18 @@ public class SatSolverTest
         Console.WriteLine(e8.ToString());
         LinearExpr e9 = LinearExpr.NewBuilder().AddWeightedSum(new BoolVar[] { b1, b2 }, c2);
         Console.WriteLine(e9.ToString());
+        LinearExpr e10 = LinearExpr.NewBuilder().Add(v1);
+        Console.WriteLine(e10.ToString());
+        LinearExpr e11 = LinearExpr.NewBuilder().Add(b1);
+        Console.WriteLine(e11.ToString());
+        LinearExpr e12 = LinearExpr.NewBuilder().Add(b1.Not());
+        Console.WriteLine(e12.ToString());
+        LinearExpr e13 = LinearExpr.NewBuilder().AddTerm(v1, -1);
+        Console.WriteLine(e13.ToString());
+        LinearExpr e14 = LinearExpr.NewBuilder().AddTerm(b1, -1);
+        Console.WriteLine(e14.ToString());
+        LinearExpr e15 = LinearExpr.NewBuilder().AddTerm(b1.Not(), -2);
+        Console.WriteLine(e15.ToString());
     }    
 
     [Fact]
diff --git a/ortools/sat/csharp/IntegerExpressions.cs b/ortools/sat/csharp/IntegerExpressions.cs
index 5aaccb58ac..a8ceaab50a 100644
--- a/ortools/sat/csharp/IntegerExpressions.cs
+++ b/ortools/sat/csharp/IntegerExpressions.cs
@@ -116,6 +116,18 @@ public class LinearExpr
         return NewBuilder().AddTerm(expr, coeff).Add(offset);
     }
 
+
+    public static LinearExpr Affine(ILiteral literal, long coeff, long offset)
+    {
+        return NewBuilder().AddTerm(literal, coeff).Add(offset);
+    }
+
+    public static LinearExpr Affine(BoolVar var, long coeff, long offset)
+    {
+        return NewBuilder().AddTerm(var, coeff).Add(offset);
+    }
+
+
     public static LinearExpr Constant(long value)
     {
         return NewBuilder().Add(value);
@@ -543,7 +555,7 @@ public class LinearExprBuilder : LinearExpr
                 }
                 else
                 {
-                    result += String.Format(" -{0}", term.expr.ToString());
+                    result += String.Format("-{0}", term.expr.ToString());
                 }
             }
             else
@@ -554,7 +566,7 @@ public class LinearExprBuilder : LinearExpr
                 }
                 else
                 {
-                    result += String.Format(" {0} * {1}", term.coefficient, term.expr.ToString());
+                    result += String.Format("{0} * {1}", term.coefficient, term.expr.ToString());
                 }
             }
         }