Hello, I am currently looking for a book on functional analysis. However most books I have seen assume knowledge real and complex analysis. But I am looking for a more superficial introduction covering the important results, some examples of applications (mainly to computational problems), and not really derivations of theorems (just intuitive explanations) etc. More like calculus for first year undergrad engineering students where integration and differentiation isn't rigorously defined but nevertheless used extensively later. Maybe one of you can point out a book for that ?