Handling infinity

True          # the object is "known infinite"
False         # the object is "known finite"
Mu            # the finiteness of the object is unknown

All three possibilities are needed for good reasoning

say (0..5).infinite                # False
say (0..Inf).infinite              # True

say (1, 1, *+* ... *).infinite     # True, implied by the '*'
say (1, 1, *+* ... 10).infinite    # Mu -- sequence can't know