Sheffer's stroke
noun
logic
a function of two sentences, equivalent to the negation of their conjunction, and written p | q (p and q are both not true) where p,q, are the arguments: p | q is false only when p,q are both true. It is possible to construct all truth functions out of this one alone
Word Origin for Sheffer's stroke
named after H. M.
Sheffer (1883–1964), US philosopher