var numberSource1 = Observable.Return(4);

var numberSource2 = Observable.Return(6);

var combiningWithFluentSyntax =

Observable

.CombineLatest(numberSource1, numberSource2, (number, otherNumber) => number + otherNumber)

.Where(sum => sum % 2 == 0)

.Select(sum => sum.ToString());

var combiningWithQuerySyntax =

from number in numberSource1

from otherNumber in numberSource2

let sum = number + otherNumber

where sum % 2 == 0

select sum.ToString();

combiningWithFluentSyntax.Subscribe(

x => Console.WriteLine("Fluent Syntax: {0}", x),

ex => Console.WriteLine("Fluent Syntax Error: {0}", ex.Message),

() => Console.WriteLine("Fluent Syntax Completed")

);

combiningWithQuerySyntax.Subscribe(

x => Console.WriteLine("Query Syntax: {0}", x),

ex => Console.WriteLine("Query Syntax Error: {0}", ex.Message),

() => Console.WriteLine("Query Syntax Completed")

);