Complex sentence: For example the expressions 5 + 6 and 7 + 4 are equal in the domain of expressions because they both map to the same literal value 11 in the domain of literal values.
Split into simpler sentences: For example the expressions 5 + 6 and 7 + 4 are equal in the domain of expressions because they both map to the same literal value 11. That is, they map to values that are equal in the domain of literal values.