Empty mi causing failure

[NSoiffer]

A Wikipedia page (first mtr, second mtd of next to last entry) starts with an empty mi. For some reason, the default intent.yaml rule dies with

Replacement
[test: [  if: 'x: "count(*) > 0"' then:[intent:  xpath-name: x: "name(.)"
      children: [x: "*"]] else:[intent:  xpath-name: x: "name(.)"
      children: [x: "text()"]]]
]
...due to matching the following MathML with the pattern
x: "."
 <mi id='M283ygl4-17' data-id-added='true'></mi>
The patterns are in C:\Users\neils\MathCAT\Rules\intent.yaml.

caused by: replacing inside 'intent'
caused by: During replacement, no matching element found

[NSoiffer]

Simple expr to reproduce:

<math><mi></mi><mo>-</mo><mi>x</mi></math>