Parcel

• Parcels represent syntactic groups of objects

    1, 2, ('hello', @a), 5/8, %h

• Parcels flatten in some contexts and itemize in others

• "parenthetical cells"

• Parcels are immutable
• (cannot push/pop a Parcel)
• elements may be mutable

• Despite the name, the comma creates Parcels
• Not the parentheses
• Except for the empty Parcel ()