mathlib3

114f8ef8 - chore(data/buffer/parser/numeral): derive mono for numeral (#5463)

chore(data/buffer/parser/numeral): derive mono for numeral (#5463) Thanks to Rob Lewis, using classes, instances, and the `delta_instance_handler`, transferring over instances becomes very easy. Co-authored-by: Yakov Pechersky <pechersky@users.noreply.github.com>