hi there

i have problem making this program its rely difficult on me

the idea of the program is (1) To parse a string to determine if it conforms to the grammar &
(2) To generate strings conforming to the grammar

this is the grammars
we must start with S that's aR
T = terminals
N= non terminals
S= star symbol
P= rules

T = {a, b, c, d} 
N = {S,R,N,P}
S = S 
P = { 
        S >> a R 
         R >>b N    
        N >> c P   
        P >> b N    
        P >> d   


Does anyone understand this...? or is it just me...