Symbol Zilde
From NARS2000
⍬ — Represents an empty numeric vector or zero plus tilde (hence zilde) — Keystroke Alt + Shift + } — Character ⎕UCS '⍬' = 9068
Usage
⌊/⍬
∞
⌈/⍬
¯∞
Symbolically zero or 0 represents number while tilde or ∼ represents not. Together the overstrike zilde symbol or ⍬ means not a number, i.e. empty numeric vector. APL frequently uses overstrike characters in dual-combined meaning, thus ⍞ which is ⎕ or prompt and the single quote symbol yielding prompt for string or character input versus ⎕ or prompt for numeric input.
Example
The above examples for infinity and negative infinity correctly run in NARS2000. In theory ONLY - ⍬ would be hypothetically equivalent to ⍳0 or 0⍴N (where N is any number) since zilde or ⍬ represents an empty numeric vector.
See Also
NARS 2000 Lang Tool Bar |
← | → | + | - | × | ÷ | * | ⍟ | ⌹ | ○ | ! | ? | √ | | | ⌈ | ⌊ | ⊥ | ⊤ | ⊣ | ⊢ | ||
= | ≠ | ≤ | < | > | ≥ | ≡ | ≢ | ∨ | ∧ | ⍱ | ⍲ | ↑ | ↓ | ⊂ | ⊃ | ⌷ | ⍋ | ⍒ | ||||
⍳ | ∊ | ⍸ | ⍷ | ∪ | ∩ | ⊆ | ⊇ | ~ | § | π | .. | , | ⍪ | ⍴ | ⌽ | ⊖ | ⍉ | |||||
/ | \ | ⌿ | ⍀ | ⊙ | ¨ | ⍨ | ⍤ | ⍦ | ⍥ | . | ∘ | ⍠ | ‼ | ⍞ | ⎕ | ⍎ | ⍕ | |||||
⋄ | ⍝ | ∇ | ∆ | ⍙ | _ | ⍺ | ⍵ | ¯ | ⍬ | ∞ | ∅ | b | e | g | p | r | v | x |