NonPositive (Built-in Mathematica Symbol)

NonPositive[x] gives True if x is a non-positive number.

NotCongruent (Built-in Mathematica Symbol)

NotCongruent[x, y, ...] displays as x \[NotCongruent] y \[NotCongruent] ....

NotDoubleVerticalBar (Built-in Mathematica Symbol)

NotDoubleVerticalBar[x, y, ...] displays as x \[NotDoubleVerticalBar] y \[NotDoubleVerticalBar] ....

NotEqualTilde (Built-in Mathematica Symbol)

NotEqualTilde[x, y, ...] displays as x \[NotEqualTilde] y \[NotEqualTilde] ....

NotExists (Built-in Mathematica Symbol)

NotExists[x, y] displays as \[NotExists] _x y.

NotGreaterEqual (Built-in Mathematica Symbol)

NotGreaterEqual[x, y, ...] displays as x \[NotGreaterEqual] y \[NotGreaterEqual] ....

NotGreaterFullEqual (Built-in Mathematica Symbol)

NotGreaterFullEqual[x, y, ...] displays as x \[NotGreaterFullEqual] y \[NotGreaterFullEqual] ....

NotGreaterGreater (Built-in Mathematica Symbol)

NotGreaterGreater[x, y, ...] displays as x \[NotGreaterGreater] y \[NotGreaterGreater] ....

NotGreater (Built-in Mathematica Symbol)

NotGreater[x, y, ...] displays as x \[NotGreater] y \[NotGreater] ....

NotGreaterSlantEqual (Built-in Mathematica Symbol)

NotGreaterSlantEqual[x, y, ...] displays as x \[NotGreaterSlantEqual] y \[NotGreaterSlantEqual] ....