Assertion: letter aleph | /r/HasProperty | printed by accident,[nb 1
Facets:
value: upside down
type: MANNER
value: in older mathematics books
type: LOCATION
value: often
type: TEMPORAL
Source sentences:
text: They are named after the symbol used to denote them, the Hebrew letter aleph (ℵ) (though in older mathematics books the letter aleph is often printed upside down by accident,[nb 1] partly because a monotype matrix for aleph was mistakenly constructed the wrong way up).