Assertion: elf | /r/HasSubevent | nightmare
Facets:
Source sentences:
text: The German word for nightmare, Alptraum, means "elf dream" while the archaic form Alpdruck means "elf pressure", which both have to do with the belief that an elf sitting on a sleeper's chest resulted in nightmares, similar to the Scandinavian belief in the mara or mera.