Catch up!
 finish with class Word from ExW6
 extend your date class with enums from ExW6
1 Finite Field Modulo 5
Take the Ring5 class from the github and modify it to a class Field5. We will use it to implement a finite field (galois field/endlicher Körper).
 provide subtraction as inverse of addition.
 can it be mapped directly to integer subtraction?
 a  a = 0
 34 = 4 <=> 4+4 = 3
 provide unary minus operator for negation
 provide division as inverse of multiplication.
 first figure out for each x (excluding 0), what y provides 1/x = y > 1 = x*y
 Does it make sense to provide relational operators for Field5?
optional Exercise
2 Ring Modulo 6
Implement a class Ring6 that implements modulo arithmetic for unsigned integers modulo 6.
 Start out with corresponding test cases, before you implement an operation.
 Provide addition and multiplication operators.
 Provide output operator to a stream.
 Provide inward and outward conversion from unsigned integers.
 When is it useful to make these conversions explicit?
 Is it useful to implement subtraction for Ring6?
 Is it useful/possible to implement division for Ring6?
Provide your answers to these questions in SolW7

Last edited August 15, 2016 
