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    <p>I haven't heard of any, but you can easily do without them if you represent the constraints as intervals:</p> <p>x > 1000 becomes (1000, double.Infinity)<br> x == 1000 becomes [1000, 1000]</p> <p>etc.</p> <p>This way you need only one class</p> <pre><code>class Constraint { double Lower; bool isLowerStrict; double Upper; bool isUpperStrict; bool isIn(double d) { return (isLowerStrict ? Lower &lt; d : Lower &lt;= d) &amp;&amp; (isUpperStrict ? Upper &gt; d : Upper &gt;= d); } Constraint intersect(Constraint other) { Constraint result = new Constraint(); if (Lower &gt; other.Lower) { result.Lower = Lower; result.isLowerStrict = isLowerStrict; } else if (Lower &lt; other.Lower) { result.Lower = other.Lower; result.isLowerStrict = other.isLowerStrict; } else { result.Lower = Lower; result.IsLowerStrict = isLowerStrict || other.isLowerStrict; } // the same for upper return result; } public bool isEmpty() { if (Lower &gt; Upper) return true; if (Lower == Upper &amp;&amp; (isLowerStrict || isUpperStrict)) return true; return false; } public bool Equals(Constraint other) { if (isEmpty()) return other.isEmpty(); return (Lower == other.Lower) &amp;&amp; (Upper = other.Upper) &amp;&amp; (isLowerStrict == other.IsLowerStrict) &amp;&amp; (isUpperStrict == other.isUpperStrict); } // construction: static Constraint GreaterThan(double d) { return new Constraint() { Lower = d, isLowerStrict = true, Upper = double.PositiveInfinity, isUpperStrict = false }; } static Constraint IsEqualTo(double d) { return new Constraint() { Lower = d, isLowerStrict = false, Upper = d, isUpperStrict = false }; } // etc. } </code></pre> <p>With this code, you can answer the questions:</p> <p>1) overlap: <code>a.Intersect(b).isEmpty()</code></p> <p>2) intersect: <code>a.Intersect(b)</code></p> <p>3) constrain: <code>a.Intersect(b).Equals(a)</code></p> <hr> <p>EDIT:<br> As @CodeInChaos suggests, you should consider replacing double with decimal. Mind that decimal lacks infinite values, so you should use decimal.MaxValue and decimal.MinValue instead.</p>
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    1. COI'd consider using `Decimal` here. That way limits parsed from text can be represented exactly.
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    2. CO@CodeInChaos: well, in that case I'd go for a generic numeric type.
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    3. CONot sure what you mean by that Vlad. You can't easily use a generic parameter in this context because the overloaded operators are missing. One can work around that using dynamic typing/runtime code generation but that's ugly and slow.
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