R1C1 Ranges don't parse properly

[CameronPattersonWTW]

The formula
=R[1]C[1]:R[2]C[2]

Does not parse properly. According to the viewer, the inner ':' is processed first resulting in this parse tree:

We can force it to parse correctly by adding parenthesis around each reference
=(R[1]C[1]):(R[2]C[2])

However excel does not require the parenthesis to know how to interpret this correctly

Also, the R[1]C[1] Style formulas are considered as the intersection of two ranges, rather than a reference that resolve's to a single cell. If you change back to A1 formulas this is resolved properly as a single cell. These issues are likely related to how R1C1 formulas are handled in the grammar