ideally fixed part of the doc for predicate-arity

prolog/metta_lang/stdlib_mettalog.metta

@@ -99,24 +99,29 @@
 
 (iz predicate-arity MeTTaLog)
 
+
 (@doc predicate-arity
   (@desc "Specifies the arity (number of arguments) for a given predicate, allowing it to be queriable in the system's match framework. This is particularly useful for enabling built-in functions, such as `size-atom`, to be used as predicates in declarative contexts and run in reverse to compute inputs based on outputs.
 
+
 For example:
   ; Enable the built-in function `size-atom` that takes an atom and returns the size
     as a predicate with arity 2
   (add-atom &dyn-space (predicate-arity size-atom 2))
 
+
   ; Now `size-atom` can be used as a predicate in pattern matching
   (match &dyn-space '(size-atom (a b c) $size) 
          (The abc tuple was len $size))
   ; This pattern will resolve `Size = 3` and execute the action.
 
+
 Additionally, by running `size-atom` in reverse, you can compute a new atom based on a desired size:
   (match &dyn-space '(size-atom $new-atom 4) 
          (The new atom is $new-atom))
   ; This resolves `$new-atom` to a tuple of size 4, such as ($1 $2 $3 $4).
 
+
 This reverse functionality is made possible because predicates can describe relationships, allowing you to infer inputs from outputs.")
   (@params (
     (@param "Predicate symbol" "The name of the predicate whose arity is being defined.")
@@ -128,33 +133,43 @@ This reverse functionality is made possible because predicates can describe rela
 (function-arity predicate-arity 1)
 
 
+
+
 (@doc function-arity
   (@desc "Defines the arity of a function, allowing predicates or built-in facts to also behave as callable functions. This enables procedural-style execution where the last argument of the predicate becomes the function's return value, and the system internally resolves the function using a `match` query. 
 
+
 For example:
-  ; Declare the built-in predicate `max` with arity 2
-  (predicate-arity max 2)
+  ; Declare the built-in predicate `max` with arity 3
+  (predicate-arity max 3)
+
 
   ; Enable `max` as a function
   (add-atom &dyn-space (function-arity max 2))
 
+
   ; Define the rules for `max`
   (add-atom &dyn-space (max $X $Y $X) (<= $X $Y))
   (add-atom &dyn-space (max $X $Y $Y) (> $X $Y))
 
+
   ; Using `max` declaratively as a predicate
   (match &dyn-space (max (5 10) $max)
          (The maximum is $max))
   ; This resolves `$max = 10`.
 
+
   ; Using `max` procedurally as a function
   (max 5 10)
   ; Returns: 10.
 
+
   ; Reverse execution with `max`
-  (max $pair 10)
+  (== (max $a $b) 10) ; as a function 
+  (max $a $b 10) ; or as a predicate
   ; Returns: a pair such as (8 10) or (10 5) where the maximum is 10.
 
+
   This dual behavior allows predicates to act as functions, bridging procedural and declarative paradigms. By defining `function-arity`, the function automatically resolves using the logic of the associated predicate.")
   (@params (
     (@param "Function symbol" "The name of the function or predicate to enable as a callable function.")
@@ -164,6 +179,7 @@ For example:
 (predicate-arity function-arity 2)
 (function-arity function-arity 1)
 
+
 ;; If Function
 
 (iz If MeTTa)