• The expression (A < B, C > D) is a tuple with two elements, each a comparison.

• The expression (A<B,C> D, E) is a tuple with two elements, the first of which is a declaration expression.

The above two statements are from C# language spec – Grammar ambiguities.

Need help to understand, why in (A < B, C > D), A < B, C > D is considered as two separate elements, and in (A<B,C> D, E), A<B,C> D is considered as a single element.