Results 2 issues of Anand Rao

This is a tactic that allows targeted unfolding of expressions in the proof state by specifying patterns and occurrences (an idea that is due to Yaël Dillies). The file `Utils.lean`...

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CC: @anshula Thanks for developing Verso! We were wondering — it seems sometimes `set_option` flags work within Verso, e.g. ```lean mysection show:=false set_option linter.unusedVariables false ``` But it seems that...