namespace System
{
    public readonly struct Single : IComparable, IComparable<float>, IConvertible, IEquatable<float>, IFormattable, IParsable<float>, ISpanFormattable, ISpanParsable<float>, IUtf8SpanFormattable, IUtf8SpanParsable<float>, IAdditionOperators<float, float, float>, IAdditiveIdentity<float, float>, IBinaryFloatingPointIeee754<float>, IBinaryNumber<float>, IBitwiseOperators<float, float, float>, IComparisonOperators<float, float, bool>, IDecrementOperators<float>, IDivisionOperators<float, float, float>, IEqualityOperators<float, float, bool>, IExponentialFunctions<float>, IFloatingPoint<float>, IFloatingPointConstants<float>, IFloatingPointIeee754<float>, IHyperbolicFunctions<float>, IIncrementOperators<float>, ILogarithmicFunctions<float>, IMinMaxValue<float>, IModulusOperators<float, float, float>, IMultiplicativeIdentity<float, float>, IMultiplyOperators<float, float, float>, INumber<float>, INumberBase<float>, IPowerFunctions<float>, IRootFunctions<float>, ISignedNumber<float>, ISubtractionOperators<float, float, float>, ITrigonometricFunctions<float>, IUnaryNegationOperators<float, float>, IUnaryPlusOperators<float, float>
    {
        public static float AcosPi(float x);
    }
}