diff --git a/operand-dict.go b/operand-dict.go
index 999c33e..ba1f6f0 100644
--- a/operand-dict.go
+++ b/operand-dict.go
@@ -4,6 +4,71 @@
 // operand-dict.go
 package expr
 
+import (
+	"fmt"
+	"reflect"
+	"strings"
+)
+
+type DictType map[any]any
+
+func newDict(dictAny []any) (dict *DictType) {
+	if dictAny != nil {
+		d := make(DictType, len(dictAny))
+		for i, item := range dictAny {
+			d[i] = item
+		}
+		dict = &d
+	}
+	return
+}
+
+func (dict *DictType) toMultiLine(sb *strings.Builder, indent int) {
+	first := true
+	for name, value := range *dict {
+		if first {
+			first = false
+		} else {
+			sb.WriteByte(',')
+			sb.WriteByte('\n')
+		}
+
+		sb.WriteString(strings.Repeat("\t", indent+1))
+		if key, ok := name.(string); ok {
+			sb.WriteString(key)
+		} else {
+			sb.WriteString(fmt.Sprintf("%v", name))
+		}
+		sb.WriteString(": ")
+		if f, ok := value.(Formatter); ok {
+			sb.WriteString(f.ToString(0))
+		} else if _, ok = value.(Functor); ok {
+			sb.WriteString("func(){}")
+		} else {
+			sb.WriteString(fmt.Sprintf("%v", value))
+		}
+	}
+	sb.WriteString(strings.Repeat("\t", indent))
+	sb.WriteString("\n}\n")
+}
+
+func (dict *DictType) ToString(opt FmtOpt) string {
+	var sb strings.Builder
+	if opt&MultiLine != 0 {
+		dict.toMultiLine(&sb, 0)
+	}
+	return sb.String()
+}
+
+func (dict *DictType) hasKey(d map[any]any, target any) (ok bool) {
+	for key := range *dict {
+		if ok = reflect.DeepEqual(key, target); ok {
+			break
+		}
+	}
+	return
+}
+
 // -------- dict term
 func newDictTerm(args map[any]*term) *term {
 	return &term{
diff --git a/operand-map.go b/operand-map.go
deleted file mode 100644
index 050e7f0..0000000
--- a/operand-map.go
+++ /dev/null
@@ -1,34 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// operand-map.go
-package expr
-
-// -------- map term
-func newMapTerm(args map[any]*term) *term {
-	return &term{
-		tk:       *NewValueToken(0, 0, SymDict, "{}", args),
-		parent:   nil,
-		children: nil,
-		position: posLeaf,
-		priority: priValue,
-		evalFunc: evalMap,
-	}
-}
-
-// -------- map func
-func evalMap(ctx ExprContext, self *term) (v any, err error) {
-	dict, _ := self.value().(map[any]*term)
-	items := make(map[any]any, len(dict))
-	for key, tree := range dict {
-		var param any
-		if param, err = tree.compute(ctx); err != nil {
-			break
-		}
-		items[key] = param
-	}
-	if err == nil {
-		v = items
-	}
-	return
-}