/// A function that takes a field element or integer and converts
/// it to a (non-negative) integer.
/// The actual implementation is replaced by a built-in function.
let int = [];

/// A function that takes a field element or integer and converts
/// it to a field element.
/// Panics if the input is negative or larger or equal to the field modulus.
/// The actual implementation is replaced by a built-in function.
let fe = [];

/// A function that takes an integer or a field element and converts it to an expression.
/// The actual implementation is replaced by a built-in function.
let expr = [];