v2.6.3

Download the library here

FIXED: Issue with (??) operator not converting the right part.

var data = new Dictionary<string, double?> { { "A", 2 }, { "B", 3 }, { "C", null } };
var result = Z.Expressions.Eval.Execute<double?>("A + B + C ?? 7", data);

Trial unlocked for the current month (May)