IntrinsicFunction  := NumericFunction | StringFunction | CastFunction | TypeFunction

NumericFunction    := NumericFunction1 | NumericFunction2 | UserFunction

NumericFunction1   := NumericIntrinsic1 | RealIntrinsic1 | UnsignedIntrinsic1
                   | '(' NumericExpression ')'
                   | '{' NumericExpression '}'
                   | '[' NumericExpression ']'

NumericFunction2   := NumericIntrinsic2 | RealIntrinsic2 | UnsignedIntrinsic2
                   | '(' NumericExpression ',' NumericExpression ')'
                   | '{' NumericExpression ',' NumericExpression '}'
                   | '[' NumericExpression ',' NumericExpression ']'

 
UnsignedIntrinsic1 := "positive"
UnsignedIntrinsic2 := "borrow"   | "carry"

NumericIntrinsic1  := "abs" | "log" | "log2" | "root"
NumericIntrinsic2  := "max" | "min" | "mod"  | "remainder"

RealIntrinsic1     := "acos   " | "acosh" | "asin" | "asinh" | "atan" | "atanh"
                      "ceiling" | "cos"   | "cosh" | "ln"    | "exp"  | "floor"
                      "integer" | "round" | "sin"  | "sinh"  | "tan"  | "tanh"

RealIntrinsic2     := "atan"



StringFunction     := StringIntrinsic | UserFunction

StringIntrinsic    := StringIndex | Substring

StringIndex        := "left" | "right" | "chop" | "trim" | "string"
                      '('  StringNumeric ')' | '{'  StringNumeric '}'
                                             | '['  StringNumeric ']'

StringNumeric      := StringExpression [ ',' NumericExpression ]

Substring          := "string" '('  SubstringIndex  ')'
                    | "string" '{'  SubstringIndex  '}'
                    | "string" '['  SubstringIndex  ']'

SubstringIndex     := StringExpression ',' NumericExpression
                                       ',' NumericExpression

CastFunction       := CastFunction1 | CastFunction2

CastFunction1      := "byte" | {Enumeration | StringExpression | NumericExpression}
                   | "byte" '(' StringExpression ',' NumericExpression ')'

                       cell
                           NumericExpression
                       parcel
                           NumericExpression | Enumeration | @Pointer
                       word
                           NumericExpression | Enumeration???
                       string
                            NumericExpression  
                       single   double
                           NumericExpression

                    | {Enumeration | StringExpression | NumericExpression}
                       cell   parcel   word   string   single   double

          byte   cell   parcel   word   string   single   double

TypeFunction    alignment(Type)
alignment(@)
 span(Type)
 span(@)
context(Variable)
signal(Variable)