# Fungrim entry: 73f5e7

Symbol: Step $f(a), f\!\left(a + 1\right), \ldots, f(b)$ Enumerated sequence
Step(f(n), For(n, a, b)) represents the sequence of values $f(n)$ for $n$ between the integers $a$ and $b$. The sequence is empty if $b < a$. This expression does not represent a mathematical object: it only exists at the expression level, and injects the sequence between a surrounding arguments. To construct a mathematical object, we must pass the generator expression to a function such as Tuple. Examples:
f(Step(Pow(k, 2), For(k, 1, 10)))
$f\!\left({1}^{2}, {2}^{2}, \ldots, {10}^{2}\right)$
Tuple(Step(Repeat(n, n), For(n, 0, N)))
$\left(\underbrace{0, \ldots, 0}_{0 \text{ times}}, \underbrace{1, \ldots, 1}_{1 \text{ times}}, \ldots, \underbrace{N, \ldots, N}_{N \text{ times}}\right)$
Tuple(1, 2, 2, Step(Repeat(n, n), For(n, 3, N)))
$\left(1, 2, 2, \underbrace{3, \ldots, 3}_{3 \text{ times}}, \underbrace{4, \ldots, 4}_{4 \text{ times}}, \ldots, \underbrace{N, \ldots, N}_{N \text{ times}}\right)$
Definitions:
Fungrim symbol Notation Short description
Pow${a}^{b}$ Power
Source code for this entry:
Entry(ID("73f5e7"),
SymbolDefinition(Step, Step(f(n), For(n, a, b)), "Enumerated sequence"),
Description(SourceForm(Step(f(n), For(n, a, b))), " represents the sequence of values ", f(n), "for ", n, "between ", "the integers", a, "and", b, ". ", "The sequence is empty if ", Less(b, a), ". ", "This expression does not represent ", "a mathematical object: it only exists at the expression level, and ", "injects the sequence between a surrounding arguments. ", "To construct a mathematical object, we must pass the generator expression ", "to a function such as", SourceForm(Tuple), ". Examples: "),
Description(SourceForm(f(Step(Pow(k, 2), For(k, 1, 10))))),
Description(f(Step(Pow(k, 2), For(k, 1, 10)))),
Description(SourceForm(Tuple(Step(Repeat(n, n), For(n, 0, N))))),
Description(Tuple(Step(Repeat(n, n), For(n, 0, N)))),
Description(SourceForm(Tuple(1, 2, 2, Step(Repeat(n, n), For(n, 3, N))))),
Description(Tuple(1, 2, 2, Step(Repeat(n, n), For(n, 3, N)))))

## Topics using this entry

Copyright (C) Fredrik Johansson and contributors. Fungrim is provided under the MIT license. The source code is on GitHub.

2021-03-15 19:12:00.328586 UTC