create implication before_common_era (19) -> ancient_period (0)
create implication 1st_century (0) -> ancient_period (0)
create implication 2nd_century (1) -> ancient_period (0)
create implication 3rd_century (1) -> ancient_period (0)
create implication 4th_century (0) -> ancient_period (0)
create implication 5th_century (0) -> ancient_period (0)
create implication 6th_century (0) -> medieval_period (0)
create implication 7th_century (1) -> medieval_period (0)
create implication 8th_century (7) -> medieval_period (0)
create implication 9th_century (2) -> medieval_period (0)
create implication 10th_century (4) -> medieval_period (0)
create implication 11th_century (7) -> medieval_period (0)
create implication 12th_century (10) -> medieval_period (0)
create implication 13th_century (5) -> medieval_period (0)
create implication 14th_century (20) -> medieval_period (0)
create implication 15th_century (39) -> medieval_period (0)
create implication 16th_century (106) -> early_modern_period (0)
create implication 17th_century (95) -> early_modern_period (0)
create implication 18th_century (157) -> early_modern_period (0)
create implication 19th_century (766) -> early_modern_period (0)