gistfile1.txt

setValue(AB) :-> A'='B /*store the relation A=>B somewhere, for example a dict() or a Hashmap*/
getValue(A)  :-> B /*load and return it from the storage*/
Operation(aBC) :-> B+C, a='+'
               :-> B-C, a='-'
               :-> B*C, a='*'
               :-> B/C, a='/'
Newline(a) :-> a; a in [\n|\r|\n\r]
Letter(a) :-> a; a in [a-zA-Z]
DigitNoZero(a) :-> a; a in [1-9]
Digit(a) :-> a; a = 0
         :-> DigitNoZero(a); alle a
LetterOrDigit(a) :-> Letter(a), all
                 :-> Digit(a), all
Number(zA) :-> (Digit(a) foreach a in A); z in (null, +)
           :-> -(Digit(a) foreach a in A); z = '-'
Name(fL) :-> Letter(f)(LetterOrDigit(l) foreach l in L), all
Call(NP) :-> Program(getValue(N)(Expression(p) for p in P)), all
Factor(aBC) :-> Expression(B), a='(' and C=')'
            :-> Number(B), a,c = null
            :-> Call(BC)
Summand(AbC) :-> Factor(A), b=null
             :-> (Operation(bFactor('1')Factor(D)) forall D in C), A=null, b in [*/], D is a Factor, C is List of 
             :-> (Operation(bFactor(A)Factor(D)) forall D in C), b in [*/], D is a Factor, C is List of Factors
Expression(AbC) :-> Summand(A) , b=null
                :-> (Operation(b Summand('1')Summand(D)) forall D in C), A=null, b in [+-], D is a Factor, C is List of 
                :-> (Operation(bSummand(A)Summand(D)) forall D in C), b in [+-]  C is a Summand, B is List of Summands
Identifier(NP) :-> Name(N)(Name(C) forall C in P), C is a ParamName, P is List of ParamNames
Assignment(AbC) :-> (setValue(Identifier(A)Expression(C)) and AbC, b='='
Line(aBc) :-> Expression(B), a in [(,null] and c in [),null]
Program(AB) :-> Line(A)(NewLine(c)Line(D) for cD in B)