Symbol Zilde: Difference between revisions
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<apll> ⌈/⍬<br /> | <apll> ⌈/⍬<br /> | ||
¯∞</apll><br /><br /> | ¯∞</apll><br /><br /> | ||
Symbolically zero or '''<apll>0</apll>''' represents '''number''' while tilde or '''<apll>{tilde}</apll>''' represents '''not.''' Together the overstrike zilde symbol or '''<apll>⍬</apll>''' means ''not a number'', i.e. empty numeric vector. APL frequently uses overstrike characters in '''dual-combined meaning,''' thus '''<apll>{quotequad}</apll>''' which is '''<apll>{quad}</apll>''' or prompt and the single quote symbol yielding ''prompt for string'' or <u>character input</u> '''versus''' '''<apll>{quad}</apll>''' or prompt for <u>numeric input</u>.<br> | |||
==Example== | ==Example== | ||
The above examples for infinity and negative infinity correctly run in NARS2000. In '''theory ONLY - {zilde}''' would be hypothetically equivalent to <apll>⍳0</apll> or <apll>0⍴N</apll> (where N is any number) since zilde or {zilde} represents an empty numeric vector. | The above examples for infinity and negative infinity correctly run in NARS2000. In '''theory ONLY - {zilde}''' would be hypothetically equivalent to <apll>⍳0</apll> or <apll>0⍴N</apll> (where N is any number) since zilde or {zilde} represents an empty numeric vector. | ||
Revision as of 20:13, 11 March 2016
⍬ — 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 |
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