Unicode: F819. Alias: Esc $z Esc. Letter-like form. Used to represent a formal parameter that will never be assigned a value.
Unicode: 224E. Infix similarity operator. x ≎ y is by default interpreted as HumpDownHump[x,y]. Used to indicate geometrical equivalence.
\[Iota]
(Mathematica Character Name) Unicode: 03B9. Aliases: Esc i Esc, Esc iota Esc. Greek letter. Not commonly used. Used in set theory to indicate an explicitly constructible set.
Unicode: 21E4. Infix arrow operator. x ⇤ y is by default interpreted as LeftArrowBar[x,y]. Sometimes used to indicate a backtab. Extensible character.
Unicode: 2199. Infix arrow operator. x ↙ y is by default interpreted as LowerLeftArrow[x,y]. Extensible character; grows by default to limited size.
Unicode: 2198. Infix arrow operator. x ↘ y is by default interpreted as LowerRightArrow[x,y]. Extensible character; grows by default to limited size.
Unicode: 2221. Letter-like form. Used in geometry to indicate an angle, as in the symbol ∡ ABC.
Unicode: 226F. Alias: Esc !> Esc. Infix ordering operator. x ≯ y is by default interpreted as NotGreater[x,y]. ≯ is equivalent to ≤ only for a totally ordered set.
Unicode: 226E. Alias: Esc !< Esc. Infix ordering operator. x ≮ y is by default interpreted as NotLess[x,y]. ≮ is equivalent to ≥ only for a totally ordered set.
\[Not]
(Mathematica Character Name) Unicode: 00AC. Aliases: Esc ! Esc, Esc not Esc. Prefix operator with built-in evaluation rules. ¬ x is by default interpreted as Not[x], equivalent to !x.