diff --git a/README.adoc b/README.adoc
index 9b1b09d..3aa75dd 100644
--- a/README.adoc
+++ b/README.adoc
@@ -63,35 +63,37 @@ package main
 import (
 	"fmt"
 	"strings"
-
 	"git.portale-stac.it/go-pkg/expr"
 )
 
 func main() {
 	ctx := expr.NewSimpleVarStore()
-	ctx.SetValue("var", int64(4))
+	ctx.SetVar("var", int64(4))
 
 	source := `(3-1)*(10/5) == var`
 
-    r := strings.NewReader(source)
-    scanner := expr.NewScanner(r, DefaultTranslations())
+	r := strings.NewReader(source)
+	scanner := expr.NewScanner(r, expr.DefaultTranslations())
 	parser := expr.NewParser(ctx)
 
 	if ast, err := parser.Parse(scanner); err == nil {
 		if result, err := ast.Eval(ctx); err == nil {
-            fmt.Printf("%q -> %v [%T]\n", source, result, result)
-        } else {
-            fmt.Println("Error calculating the expression:", err)
-        }
+			fmt.Printf("%q -> %v [%T]\n", source, result, result)
+		} else {
+			fmt.Println("Error calculating the expression:", err)
+		}
 	} else {
-        fmt.Println("Error parsing the expression:", err)
-    }
+		fmt.Println("Error parsing the expression:", err)
+	}
 }
 ----
+
 The above program is equivalent to the following one.
 
 [source,go]
 ----
+package main
+
 import (
 	"fmt"
 	"git.portale-stac.it/go-pkg/expr"
@@ -99,15 +101,38 @@ import (
 
 func main() {
 	ctx := expr.NewSimpleVarStore()
-	ctx.SetValue("var", int64(4))
+	ctx.SetVar("var", int64(4))
 
 	source := `(3-1)*(10/5) == var`
 
-    if result, err := expr.EvalString(ctx, source); err == nil {
-        fmt.Printf("%q -> %v [%T]\n", source, result, result)
-    } else {
-        fmt.Println("Error calculating the expression:", err)
-    }
+	if result, err := expr.EvalString(ctx, source); err == nil {
+		fmt.Printf("%q -> %v [%T]\n", source, result, result)
+	} else {
+		fmt.Println("Error calculating the expression:", err)
+	}
+}
+----
+
+Here is another equivalent version.
+
+[source,go]
+----
+package main
+
+import (
+	"fmt"
+
+	"git.portale-stac.it/go-pkg/expr"
+)
+
+func main() {
+	source := `(3-1)*(10/5) == var`
+
+	if result, err := expr.EvalStringA(source, expr.Arg{"var", int64(4)}); err == nil {
+		fmt.Printf("%q -> %v [%T]\n", source, result, result)
+	} else {
+		fmt.Println("Error calculating the expression:", err)
+	}
 }
 ----