I interpreted (maybe misinterpreted) that as lamenting having to write out priorities of operators, as that's the most common set of rules in BNF where you end up with near identical permutations. E.g:
term = term2 [op1 term]
term2 = term3 [op2 term2]
... and so on for every precedence level. A lot of BNF grammars for simpler languages are dominated by rules following that pattern.
term = term2 [op1 term]
term2 = term3 [op2 term2]
... and so on for every precedence level. A lot of BNF grammars for simpler languages are dominated by rules following that pattern.