You have a collision. Collisions between interface methods can always be resolved providing the following three conditions apply:
1: The methods have the same signature. (Otherwise it is overloading and not a collision at all).2: The methods have compatible intent (see below).3: The methods have the same return type. (You will have to check in the Java Language Specification for the exact details.)You are violating no 3 here, and it will never compile.
This is overloading
And this is incompatible intent
Obviously the WackyArithmetic#add method is only suitable for jokes, but I challenge you to implement both those interfaces in accordance with their specifications given.
Have a look at these three add methods: note that the first is intentionally given a vague specification so both sub-interfaces can implement it differently, but still be compatible in intent.
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