Fix typo in tuple equality proposal (dotnet#3614)

Author: pkulikov

proposals/csharp-7.3/tuple-equality.md

@@ -17,7 +17,7 @@ This proposal adds a tuple case between (1) and (2): if both operands of a compa
 
 Both operands (and, in the case of tuple literals, their elements) are evaluated in order from left to right. Each pair of elements is then used as operands to bind the operator `==` (or `!=`), recursively. Any elements with compile-time type `dynamic` cause an error. The results of those element-wise comparisons are used as operands in a chain of conditional AND (or OR) operators.
 
-For instance, in the context of `(int, (int, int)) t1, t2;`, `t1 == (1, (2, 3))` would evaluate as `temp1.Item1 == temp2.Item1 && temp1.Item2.Item1 == temp2.Item2.Item1 && temp2.Item2.Item2 == temp2.Item2.Item2`.
+For instance, in the context of `(int, (int, int)) t1, t2;`, `t1 == (1, (2, 3))` would evaluate as `temp1.Item1 == temp2.Item1 && temp1.Item2.Item1 == temp2.Item2.Item1 && temp1.Item2.Item2 == temp2.Item2.Item2`.
 
 When a tuple literal is used as operand (on either side), it receives a converted tuple type formed by the element-wise conversions which are introduced when binding the operator `==` (or `!=`) element-wise.