LP allows users to employ

- opening symbols:
`[`,`{`,`\(`,`\<` - closing symbols:
`]`,`}`,`\)`,`\>`

enable the following notations:declare operators {}: -> Set {__}: Nat -> Set __[__]: Array, Nat -> Nat __[__,__]: Matrix, Nat, Nat -> Nat [__]__: Nat, Matrix -> Array ..

- empty set:
`{}` - singleton set:
`{x}` - element of an array:
`a[n]` - element of a matrix:
`m[1, 2]` - slice of a matrix:
`[1]m`