diff --git a/include/xo/type/Metatype.hpp b/include/xo/type/Metatype.hpp
index 8f7fc62..9ff612a 100644
--- a/include/xo/type/Metatype.hpp
+++ b/include/xo/type/Metatype.hpp
@@ -48,6 +48,9 @@ namespace xo {
                 /** any numeric type: i16|i32|i64|f32|f64 **/
                 t_numeric,
 
+                /** generalized boolean type: bool, function with bool codomain **/
+                t_booleic,
+
                 /** any callable type (e.g. all function types) **/
                 t_callable,
 
@@ -78,6 +81,7 @@ namespace xo {
             static Metatype t_dict()     { return Metatype(code::t_dict);     }
             static Metatype t_integer()  { return Metatype(code::t_integer);  }
             static Metatype t_numeric()  { return Metatype(code::t_numeric);  }
+            static Metatype t_booleic()  { return Metatype(code::t_booleic);  }
             static Metatype t_callable() { return Metatype(code::t_callable); }
             static Metatype t_any()      { return Metatype(code::t_any);      }
 
diff --git a/src/type/Metatype.cpp b/src/type/Metatype.cpp
index aa1a1bb..1ac26f6 100644
--- a/src/type/Metatype.cpp
+++ b/src/type/Metatype.cpp
@@ -31,6 +31,7 @@ namespace xo {
             case code::t_dict:     return "dict";
 
             case code::t_integer:  return "integer";
+            case code::t_booleic:  return "booleic";
             case code::t_numeric:  return "numeric";
             case code::t_callable: return "callable";
             case code::t_any:      return "any";
@@ -76,6 +77,8 @@ namespace xo {
 
             case code::t_integer:
                 return true;
+            case code::t_booleic:
+                return true;
             case code::t_numeric:
                 return true;
             case code::t_callable: