Answer:
2
The mathematical expression 1+1 can be evaluated differently depending on the context. In ordinary arithmetic, it results in the number 2. However, in Boolean algebra with a notation where '+' represents a logical disjunction, it evaluates to the number 1. Furthermore, in Boolean algebra with a notation where '+' denotes the 'exclusive or' operation, or in a quotient ring of numbers modulo 2, the expression 1+1 yields the number 0.