• ← Unequal

UnsameQ (=!=)

WMA link

UnsameQ[x, y]

x =!= y

returns True if x and y are not structurally identical.
Commutative properties apply, so if x =!= y, then y =!= x.

• • a =!= a

• • 1 =!= 1.

UnsameQ accepts any number of arguments and returns True if all expressions
are structurally distinct:

• • 1 =!= 2 =!= 3 =!= 4

UnsameQ returns False if any expression is identical to another:

• • 1 =!= 2 =!= 1 =!= 4

UnsameQ[] and UnsameQ[expr] return True:

• • UnsameQ[]

• • UnsameQ[expr]