darkfi/doc/src/spec/notation.md

Notation

We use superscript$^*$ to denote an arbitrary length ordered array, usually corresponding to the Vec type in Rust.

ℕ denotes the non-negative integers. ℕ₆₄ denotes ℕ restricted to the range corresponding to u64 in Rust of [0, 2⁶⁴).

𝔹 denotes a single byte [0, 2⁸) corresponding to u8 in Rust. We use 𝔹^* for an arbitrary sequence of bytes. Use ℕ2𝔹ⁿ : ℕ₈ₙ → 𝔹ⁿ for converting between the integer ℕ₈ₙ to 𝔹ⁿ in little-endian order.

𝔹ᵃ||𝔹ᵇ with a, b ∈ ℕ is used for concatenation of arbitrary bytes.

ℤ₂ refers to binary bits.

\t{im}(f) denotes the image of a function f.

[n] with n ∈ ℕ denotes the sequences of n values starting with 1.