The

diagonal fraction bar in

mathematics. Also called

virgule or

slash. This

symbol was used to

replace the

horizontal fraction

bar, sometimes referred to as a

vinculum, due to the

typographic difficulty imposed by the horizontal bar which requires three

terraces of

type.

An early written example of this usage can be found in a 1718 ledger by Thomas Twining. In his article "The Calculations of Functions" from 1845 and published in the Encyclopaedia Metropolitana, De Morgan recommended the use of the solidus.

Also, an ancient Roman gold coin used until the fall of the Byzantine Empire and introduced by Constantine.