According to the above example, write the mathematical relations $($equations$)$ used for encryption $[$E$($X$)]$ and decryption $[$D$($Y$)]$ functions.substitution table:

$\backslash$table$[[A,B,C,D,E,F,G,H,1,J,K,L,M,N,O,P,O,R,S,T,U,V,W,x,Y,Z$