Terminologies
lhs : Left Hand Side
rhs : Right Hand Side
p = q : an identity
Equational Expression: expr1 = exper2expr2 e.g. expr1 = a*x+b and expr2 = cos[b-c]
copycopy: when an object is duplicated ,duplicated, byte by byte so to saysay, tointo a facsimile.
This definition of copy is the simplest to grasp the concept. In due places, more sophisticated definitions will be produced.