This member is added by an implicit conversion from RichExpansionSequent to
any2stringadd[RichExpansionSequent] performed by method any2stringadd in scala.Predef.
This member is added by an implicit conversion from RichExpansionSequent to
StringFormat[RichExpansionSequent] performed by method StringFormat in scala.Predef.
Extension class that allows calling shallow and deep on sequents.