formal grammar of mex with left recursion

[lagleki]

Describe the current content chapter 21:

mex-1 311 = mex-2 [BIhE # operator mex-1]

Section 18.20:

By default, Lojban mathematics is like simple calculator mathematics: there is no notion of “operator precedence”. Consider the following example, where pi'i means “times” , the multiplication operator:

Example 18.28. 

li	ci	su'i	vo	pi'i	mu	du	li	reci
The-number	three	plus	four	times	five	equals	the-number	two-three.
3 + 4 × 5 = 23

The two section contradict each other.

Proposed content

mex = mex-1
mex = mex operator mex-1

Additional context

Necessary for evaluating mekso expressions.