/// This is a built-in function taking a string argument and terminating
/// evaluation unsuccessfully with this argument as explanation.
/// This symbol is not an empty array, the actual semantics are overridden.
let panic = [];

/// Checks the condition and panics if it is false.
/// IMPORTANT: Since this does not generate any constraints, the verifier will not
/// check these assertions. This function should only be used to verify
/// prover-internal consistency.
/// The panic message is obtained by calling the function `reason`.
/// Returns an empty array on success, which allows it to be used at statement level.
let assert = |condition, reason| if !condition { panic(reason()) } else { [] };