DMNFTF — FEEL grammar should define precedence of boxed expressions

It is unclear whether the following is syntactically correct

{x:1}.x=1

or whether the following must be used:

({x:1}).x=1

The intent is that both are correct.

Split grammar rule 1 into 1a and 1b and note in the 'Additional Syntax Rules':

Operator precedence is given by the order of the alternatives in grammar rules 1, 2 and 4. E.g., (boxed) invocation has higher precedence than multiplication, multiplication has higher precedence than addition, and addition has higher precedence than comparison. Addition and subtraction have equal precedence, and like all FEEL infix binary operators, are left associative.