Is your feature request related to a problem? Please describe.

Currently if one calls exponent after some operator then this operator will be considered as a base of a power.

Describe the solution you'd like

Appearing of a new placeholder with both "empty" parts.

Describe alternatives you've considered

Disallow using of exponent if previous atom isn't appropriate.

Difficulty: How difficult would it be? (Trivial, Very Easy, Easy, Moderate, Hard, Very Hard, Tedious, Backbreaking)

I'd say it's a Moderate. I tried to create a very quick sketch and though MathList looked right placeholder had been placed in the wrong position. Unsure why.

Additional context