remove alias 1521 (1) -> 16th_century (106)
change category 1616 (1) -> meta
change category 1618 (1) -> meta
change category 1640 (1) -> meta
change category 1667 (1) -> meta
change category 1791 (2) -> meta
create implication 1616 (1) -> 17th_century (95)
create implication 1618 (1) -> 17th_century (95)
create implication 1640 (1) -> 17th_century (95)
create implication 1667 (1) -> 17th_century (95)
create implication 1791 (2) -> 18th_century (157)