@@ -33,29 +33,24 @@ return scope.symbols[key]
   elif not scope.parent.isNil:
     return scope.parent.getSymbol(key)
 
-proc delSymbol*(scope: ref MinScope, key: string) =
+proc delSymbol*(scope: ref MinScope, key: string): bool {.discardable.}=
   #echo key, " - ", scope.symbols.hasKey(key)
   if scope.symbols.hasKey(key):
     scope.symbols.excl(key)
-  elif not scope.parent.isNil:
-    scope.parent.delSymbol(key)
+    return true
+  return false
 
 proc setSymbol*(scope: ref MinScope, key: string, value: MinOperator): bool {.discardable.}=
   result = false
-  # check if a symbol already exists in parent scope
-  if not scope.parent.isNil and scope.parent.symbols.hasKey(key):
-    scope.parent.symbols[key] = value
-    #echo "($1) SET EXISTING SYMBOL: $2" % [scope.parent.fullname, key]
-    return true
+  # check if a symbol already exists in current scope
+  if not scope.isNil and scope.symbols.hasKey(key):
+    scope.symbols[key] = value
+    #echo "($1) SET EXISTING SYMBOL: $2" % [scope.fullname, key]
+    result = true
   else:
     # Go up the scope chain and attempt to find the symbol
     if not scope.parent.isNil:
       result = scope.parent.setSymbol(key, value)
-  if not result:
-    # Define local variable
-    #echo "($1) SET LOCAL SYMBOL: $2" % [scope.fullname, key]
-    scope.symbols[key] = value
-    return true
 
 proc getSigil*(scope: ref MinScope, key: string): MinOperator =
   if scope.sigils.hasKey(key):

@@ -37,7 +37,7 @@ echo "Debugging: $1" % [$i.debugging]
 
   # Language constructs
 
-  .symbol("let") do (i: In):
+  .symbol("define") do (i: In):
     var q2 = i.pop # new (can be a quoted symbol or a string)
     var q1 = i.pop # existing (auto-quoted)
     var symbol: string
@@ -50,7 +50,7 @@ symbol = q2.qVal[0].symVal
     else:
       i.error errIncorrect, "The top quotation must contain only one symbol value"
       return
-    i.debug "[let] " & symbol & " = " & $q1
+    i.debug "[define] " & symbol & " = " & $q1
     i.scope.symbols[symbol] = proc(i: var MinInterpreter) =
       #i.evaluating = true
       #i.filename = q1.filename # filename will be reset automatically by interpreter
@@ -74,7 +74,7 @@ i.debug "[bind] " & symbol & " = " & $q1
     #if not i.filename.isNil and i.filename != "eval":
     #  echo "BIND $1 - fn: $2" % [symbol, i.filename]
     #  q1.filename = i.filename # Save filename for diagnostic purposes
-    i.scope.setSymbol(symbol) do (i: In):
+    let res = i.scope.setSymbol(symbol) do (i: In):
       #i.evaluating = true
       let fn = i.filename
       #if not q1.filename.isNil:
@@ -83,12 +83,16 @@ #echo "BIND '$1' FN: $2" % [symbol, i.filename]
       i.push q1.qVal
       #i.filename = fn
       #i.evaluating = false
+    if not res:
+      i.error errRuntime, "Attempting to bind undefined symbol: " & symbol
 
   .symbol("delete") do (i: In):
     var sym = i.pop
     if not sym.isStringLike:
       i.error errIncorrect, "A string or a symbol are required on the stack"
-    i.scope.delSymbol(sym.getString) 
+    let res = i.scope.delSymbol(sym.getString) 
+    if not res:
+      i.error errRuntime, "Attempting to delete undefined symbol: " & sym.getString
 
   .symbol("module") do (i: In):
     let name = i.pop
@@ -168,43 +172,74 @@ i.error(errIncorrect, "A string is required on the stack")
 
 
   .symbol("call") do (i: In):
-    let fqn = i.pop
-    if fqn.isQuotation:
-      let vals = fqn.qVal
-      var q: MinValue
-      if vals.len == 0:
-        i.error(errIncorrect, "No symbol to call")
+    let symbols = i.pop
+    if not symbols.isQuotation:
+      i.error(errIncorrect, "A quotation is required on the stack")
+    let vals = symbols.qVal
+    var q: MinValue
+    if vals.len == 0:
+      i.error errIncorrect, "No symbol to call"
+      return
+    let origScope = i.scope
+    for c in 0..vals.len-1:
+      if not vals[c].isStringLike:
+        i.error(errIncorrect, "Quotation must contain only symbols or strings")
+        return
+      let symbol = vals[c].getString
+      let qProc = i.scope.getSymbol(symbol)
+      if qProc.isNil:
+        i.error(errUndefined, "Symbol '$1' not found in scope '$2'" % [symbol, i.scope.fullname])
         return
-      var symScope = i.scope
-      var symFilename = i.filename
-      for c in 0..vals.len-1:
-        if not vals[c].isStringLike:
-          i.error(errIncorrect, "Quotation must contain only symbols or strings")
+      qProc(i)
+      if vals.len > 1 and c < vals.len-1:
+        q = i.pop
+        if not q.isQuotation:
+          i.error(errIncorrect, "Unable to evaluate symbol '$1'" % [symbol])
           return
-        let qProc = i.scope.getSymbol(vals[c].getString)
-        if qProc.isNil:
-          i.error(errUndefined, "Symbol '$1' not found" % [vals[c].getString])
-          return
-        let currScope = i.scope
-        let currFilename = i.filename
-        # Execute operator in "parent" symbol scope
-        #echo "CALL - executing '$1' fn: $2" % [vals[c].getString, "-"]
-        i.scope = symScope
-        #i.filename = symFilename
-        #echo ">>> CALL: ", vals[c].getString, " - ", symFilename
-        qProc(i)
-        i.scope = currScope
-        #echo "<<< CALL: ", currFilename
-        #i.filename = currFilename
-        if vals.len > 1 and c < vals.len-1:
-          q = i.pop
-          if not q.isQuotation:
-            i.error(errIncorrect, "Unable to evaluate symbol '$1'" % [vals[c-1].getString])
-            return
-          symScope = q.scope
-          symFilename = q.filename
-    else:
-      i.error(errIncorrect, "A quotation is required on the stack")
+        i.scope = q.scope 
+    i.scope = origScope
+
+     
+
+
+#  .symbol("call") do (i: In):
+#    let fqn = i.pop
+#    if fqn.isQuotation:
+#      let vals = fqn.qVal
+#      var q: MinValue
+#      if vals.len == 0:
+#        i.error(errIncorrect, "No symbol to call")
+#        return
+#      var symScope = i.scope
+#      var symFilename = i.filename
+#      for c in 0..vals.len-1:
+#        if not vals[c].isStringLike:
+#          i.error(errIncorrect, "Quotation must contain only symbols or strings")
+#          return
+#        let qProc = i.scope.getSymbol(vals[c].getString)
+#        if qProc.isNil:
+#          i.error(errUndefined, "Symbol '$1' not found in scope '$2'" % [vals[c].getString, i.scope.fullname])
+#          return
+#        let currScope = i.scope
+#        let currFilename = i.filename
+#        # Execute operator in "parent" symbol scope
+#        #echo "CALL - executing '$1' fn: $2" % [vals[c].getString, "-"]
+#        i.scope = symScope
+#        #i.filename = symFilename
+#        #echo ">>> CALL: ", vals[c].getString, " - ", symFilename
+#        qProc(i)
+#        i.scope = currScope
+#        #echo "<<< CALL: ", currFilename
+#        #i.filename = currFilename
+#        if vals.len > 1 and c < vals.len-1:
+#          q = i.pop
+#          if not q.isQuotation:
+#            i.error(errIncorrect, "Unable to evaluate symbol '$1'" % [vals[c-1].getString])
+#            return
+#          symScope = q.scope
+#          symFilename = q.filename
+#    else:
+#      i.error(errIncorrect, "A quotation is required on the stack")
 
 
   # Operations on the whole stack

@@ -10,8 +10,8 @@ #sys
 #time
 
 ; Common sigils
-(bind)            (:)     sigil 
-(let)             (.)     sigil 
+(bind)            (.)     sigil 
+(define)          (:)     sigil 
 (delete)          (~)     sigil 
 (getenv)          ($)     sigil 
 (system)          (!)     sigil 
@@ -21,8 +21,8 @@ (load)            (@)     sigil
 (":" split call)  (%)     sigil
 
 ; Aliases
-'bind        ::
-'let         :.
+'define      ::
+'bind        :.
 'module      :=
 'import      :#
 'exit        :quit
@@ -71,6 +71,6 @@ ((() cons cons) dip swap i)       :bury2
 ((() cons cons cons) dip swap i)  :bury3
 
 ; Other
-(print pop)    :print!
+(print pop)   :print!
 (put pop)     :put!
 

@@ -9,14 +9,16 @@ (sigils size 11 ==) assert
 
   (debug? false ==) assert
 
-  (2 'a let
-    (3 a + (5 'a let a) -> +) -> a + 12 ==) assert
+  (2 'a define
+    (3 a + (5 'a define a) -> +) -> a + 12 ==) assert
 
   (symbols "a" contains false ==) assert
-
-  (5 'five : symbols "five" contains) assert
-
-  ("five" delete symbols "five" contains false  ==) assert
+  
+  5 :five
+  (symbols "five" contains) assert
+  
+  ~five
+  (symbols "five" contains false  ==) assert
 
   (
     (
@@ -69,8 +71,8 @@ 
   ((2 3 >) ("YES") ("NO") ifte "NO" ==) assert
   ((2 3 <) ("YES") ("NO") ifte "YES" ==) assert
 
-  (0 .c
-    (c 10 <) (c succ :c) while
+  (0 :c
+    (c 10 <) (c succ .c) while
     c 10 ==) assert
 
   ((1 2 3 4 5) (even?) filter (2 4) ==) assert

@@ -1,11 +1,11 @@ 
 ;; test module
 (
- 'OK ' .ok
- ("  " print!) .padding
+ 'OK ' :ok
+ ("  " print!) :padding
 
  ;; describe
  (
-   .name
+   :name
    "Testing: [" print! name print! "]" put! 
    padding
    () 
@@ -13,8 +13,8 @@ ) :describe
 
  ;; assert
  (
-  ' .check      ; save the check quotation to validate
-  ' .results    ; save the result symbol to update
+  ' :check      ; save the check quotation to validate
+  ' :results    ; save the result symbol to update
   (check -> true ==)
   ( 
     ok results append quote :results 
@@ -31,16 +31,16 @@ 
  ;; report
  (
   newline
-  ' .results ; save the results collected so far
-  0 .total
-  0 .failed
+  ' :results ; save the results collected so far
+  0 :total
+  0 :failed
   results (
-    total succ :total
-    (ok !=) (failed succ :failed) () ifte
+    total succ .total
+    (ok !=) (failed succ .failed) () ifte
   ) map
   padding total print! " tests executed - " print! failed print! " failed." put!
   (
-    ' .result
+    ' :result
     result
     (ok !=)
     (padding "FAILED: " print! result put!)