Grep expression for m3 ha−1

Question

I tried to replace m3 ha−1 into m³ ha⁻¹ with no success. What is wrong with my expression?

(?i)(?<=\<m)3(?= ha\>)-1

Answer 1

The superscript dash is different than the one you use in the Grep:

m3 ha−1: has a long dash

(?i)(?<=\)-1: has a short dash

Is it not enough this way?

(?<=ha)-1|(?<=m)3