Function index

Here is a table of symbols we have used and how to type them in TryAPL.

It might be useful to review this page as you are doing the read and write exercises in the next sections.

New functions

Execute and format

Symbol	Name	Function (Monadic/Dyadic)	Key combination (Prefix)	Key combination (Tab)
`⍎`	Hydrant	Execute	`PREFIX` `;`	`o` `_` `Tab`
`⍕`	Thorn	Format / Format by specification	`PREFIX` `'`	`o` `T` `Tab`

Inner and outer products

Symbol	Name	Function (Monadic/Dyadic)	Key combination (Prefix)	Key combination (Tab)
`∘.`	Jot dot	Outer product	`PREFIX` `J` then `.`	`o` `o` `Tab` then `.`
`.`	Dot	Inner product	`.`	`.`
`⌹`	Domino	Matrix inverse / Matrix divide	`PREFIX` `+`	`[` `-` `Tab`

Encoding and decoding

Symbol	Name	Function (Monadic/Dyadic)	Key combination (Prefix)	Key combination (Tab)
`⊤`	Down tack	Encode	`PREFIX` `N`	`T` `T` `Tab`
`⊥`	Up tack	Decode	`PREFIX` `B`	`\|` `_` `Tab`

Repeat and masking

Symbol	Name	Function (Monadic/Dyadic)	Key combination (Prefix)	Key combination (Tab)
`⍣`	Star diaeresis	Power, Until	`PREFIX` `Shift`+`P`	`*` `:` `Tab`
`@`	At	At	`@`	`@`

User-defined operators

Symbol	Name	Function (Monadic/Dyadic)	Key combination (Prefix)	Key combination (Tab)
`⍺⍺`	Alpha alpha	Left operand	`PREFIX` `A` (twice)	`a` `a` `Tab` (twice)
`⍵⍵`	Omega omega	Right operand	`PREFIX` `W` (twice)	`w` `w` `Tab` (twice)
`∇`	Del	Derived function	`PREFIX` `G`	`V` `V` `Tab`
`∇∇`	Double del	Recursion	`PREFIX` `G` (twice)	`V` `V` `Tab` (twice)

System variables and constants

Name	Meaning
`⎕A`	The upper-case English alphabet, `'ABCDEFGHIJKLMNOPQRSTUVWXYZ'`
`⎕CT`	Comparison tolerance, from `0` (exact comparison) up to `10*¯10`
`⎕PP`	Print precision, the number of digits displayed
`⎕IO`	Index origin, either `1` (the default) or `0`

Old functions

Symbol	Name	Function (Monadic/Dyadic)	Key combination (Prefix)	Key combination (Tab)
`+`	Plus	Conjugate / Plus	`+`	`+`
`-`	Minus	Negate / Minus	`-`	`-`
`×`	Times	Direction / Times	`PREFIX` `-`	`x` `x` `Tab`
`÷`	Divide	Divide	`PREFIX` `=`	`:` `-` `Tab`
`*`	Star	Power	`*`	`*`
`¯`	High minus	Negative	`PREFIX` `2`	`-` `-` `Tab`
`⍝`	Lamp	Comment	`PREFIX` `,`	`o` `n` `Tab`
`←`	Assignment symbol	Assign	`PREFIX` `[`	`<` `-` `Tab`
`⎕`	Quad	Output	`PREFIX` `L`	`[` `]` `Tab`
`⍴`	Rho	Shape / Reshape	`PREFIX` `R`	`r` `r` `Tab`
`,`	Comma	Ravel / Catenate	`,`	`,`
`{}`	Braces	Dfn	`{` `}`	`{` `}`
`⍺`	Alpha	Left argument	`PREFIX` `A`	`a` `a` `Tab`
`⍵`	Omega	Right argument	`PREFIX` `W`	`w` `w` `Tab`
`⋄`	Diamond	Statement separator	`PREFIX` `	`<` `>` `Tab`
`⍬`	Zilde	Empty numeric vector	`PREFIX` `}`	`0` `~` `Tab`
`⌈`	Upstile	Ceiling / Maximum	`PREFIX` `S`	`7` `7` `Tab`
`⌊`	Downstile	Floor / Minimum	`PREFIX` `D`	`l` `l` `Tab`
`\|`	Stile	Magnitude / Residue	`PREFIX` `M`	`\|`
`∨`	Logical OR	Greatest common divisor, Or	`PREFIX` `9`	`v` `v` `Tab`
`∧`	Logical AND	Lowest common multiple, And	`PREFIX` `0`	`^` `^` `Tab`
`○`	Circle	Pi times / Circular	`PREFIX` `O`	`O` `O` `Tab`
`!`	Exclamation mark	Factorial / Binomial	`PREFIX` `_`	`!`
`=`	Equal	Equal to	`PREFIX` `5`	`=`
`≠`	Not equal	Not equal to	`PREFIX` `8`	`=` `/` `Tab`
`<`	Less than	Less than	`PREFIX` `3`	`<`
`≤`	Less than or equal to	Less than or equal to	`PREFIX` `4`	`<` `=` `Tab`
`>`	Greater than	Greater than	`PREFIX` `7`	`>`
`≥`	Greater than or equal to	Greater than or equal to	`PREFIX` `6`	`>` `=` `Tab`
`≡`	Equal underbar	Depth / Match	`PREFIX` `:`	`=` `=` `Tab`
`~`	Tilde	Not / Without	`PREFIX` `T`	`~`
`⍲`	Up caret tilde	Nand	`PREFIX` `)`	`^` `~` `Tab`
`⍱`	Down caret tilde	Nor	`PREFIX` `(`	`v` `~` `Tab`
`∇`	Del	Recursion	`PREFIX` `G`	`V` `V` `Tab`
`:`	Colon	Guard	`:`	`:`
`⊣`	Left tack	Same / Left	`PREFIX` `\|`	`-` `\|` `Tab`
`⊢`	Right tack	Same / Right	`PREFIX` `\`	`\|` `-` `Tab`
`⍤`	Jot diaeresis	Rank / Atop	`PREFIX` `Shift`+`J`	`o` `:` `Tab`
`∘`	Jot	Bind	`PREFIX` `J`	`o` `o` `Tab`
`⍨`	Tilde diaeresis	Swap, Self	`PREFIX` `Shift`+`T`	`~` `:` `Tab`
`⍳`	Iota	Index generator / Index of	`PREFIX` `I`	`i` `i` `Tab`
`?`	Question mark	Roll / Deal	`PREFIX` `Q`	`?`
`/`	Slash	Replicate, Compress, Reduce	`/`	`/`
`\`	Backslash	Scan	`\`	`\`
`⍋`	Grade up	Grade up	`PREFIX` `$`	`A` `\|` `Tab`
`⍒`	Grade down	Grade down	`PREFIX` `#`	`V` `\|` `Tab`
`↑`	Up arrow	Mix / Take	`PREFIX` `Y`	`^` `\|` `Tab`
`↓`	Down arrow	Split / Drop	`PREFIX` `U`	`v` `\|` `Tab`
`[]`	Brackets	Index, Bracket axis	`[` `]`	`[` `]`
`⊃`	Right shoe	Pick	`PREFIX` `X`	`)` `)` `Tab`
`∊`	Epsilon	Enlist / Member of	`PREFIX` `E`	`e` `e` `Tab`
`⍸`	Iota underbar	Where / Interval index	`PREFIX` `Shift`+`I`	`i` `_` `Tab`
`⍷`	Epsilon underbar	Find	`PREFIX` `Shift`+`E`	`e` `_` `Tab`
`⌸`	Quad equal	Key	`PREFIX` `Shift`+`K`	`[` `=` `Tab`
`∪`	Down shoe	Unique / Union	`PREFIX` `V`	`u` `u` `Tab`
`∩`	Up shoe	Intersection	`PREFIX` `C`	`n` `n` `Tab`
`⊂`	Left shoe	Enclose / Partitioned enclose	`PREFIX` `Z`	`(` `(` `Tab`
`¨`	Diaeresis	Each	`PREFIX` `1`	`:` `:` `Tab`
`⌿`	Slash bar	Reduce first	`PREFIX` `/`	`/` `-` `Tab`
`⌷`	Squad	Index	`PREFIX` `Shift`+`L`	`[` `\|` `Tab`
`⍪`	Comma bar	Table / Catenate first	`PREFIX` `<`	`,` `-` `Tab`
`⍉`	Circle backslash	Transpose / Reorder axes	`PREFIX` `^`	`O` `\` `Tab`
`⌽`	Circle stile	Reverse / Rotate	`PREFIX` `%`	`O` `\|` `Tab`
`⊖`	Circle bar	Reverse first / Rotate first	`PREFIX` `&`	`O` `-` `Tab`
`⊆`	Left shoe underbar	Partition	`PREFIX` `Shift`+`Z`	`(` `_` `Tab`