// SPDX-License-Identifier: MIT
// Generated by EML-lang Solidity backend
// Source module: soft_actuator
// Source file:   /home/monogate/monogate/forge/examples/soft_actuator.eml
// Functions:     1 (1 @verify-annotated)
// Constants:     2
// Transcendental stubs: tanh -- override in a derived contract (see PRBMath SD59x18)

pragma solidity ^0.8.20;

contract SoftActuator {
    int256 constant OUT_MIN = (-1);
    int256 constant OUT_MAX = 1;

    /// @notice Formal proof: soft_actuator_within_band (MachLib). Compiled from EML-lang.
    /// @dev Pfaffian profile: chain_order=1, cost_class=p1-d4-w1-c0, drift_risk=MEDIUM.
    /// @dev Gas estimate: ~7,300 gas (PRBMath SD59x18 overrides assumed; run forge gas-bench for the canonical signal).
    /// @param error error (int256)
    /// @param gain gain (int256)
    /// @dev ensures: (result >= OUT_MIN)
    /// @dev ensures: (result <= OUT_MAX)
    function softActuator(int256 error, int256 gain) external pure returns (int256) {
        require(((error < 0 ? -error : error) <= 100), "soft_actuator: refinement violated on error: ((error < 0 ? -error : error) <= 100)");
        require(((gain < 0 ? -gain : gain) <= 10), "soft_actuator: refinement violated on gain: ((gain < 0 ? -gain : gain) <= 10)");
        int256 raw = _tanh((gain * error));
        return _clamp(raw, OUT_MIN, OUT_MAX);
    }

    /// @dev clamp helper -- min(max(x, lo), hi).
    function _clamp(int256 x, int256 lo, int256 hi) internal pure returns (int256) {
        if (x < lo) return lo;
        if (x > hi) return hi;
        return x;
    }

    /// @dev tanh stub — override with a fixed-point implementation.
    function _tanh(int256 x) internal pure virtual returns (int256) {
        x; // silence unused-param warning
        revert("_tanh: stub — override in a derived contract (see PRBMath SD59x18.tanh)");
    }

}