IsFalse !

[gwholdom]

In the IsFalse method I think you're missing a !

RunExpression(Message, c => predicate(c(_model)), property);
should be
RunExpression(Message, c => !predicate(c(_model)), property);

Love the code = good job!

[dustindavis]

Fixed. I also updated the language to be a bit more expressive and explicit.

[gwholdom]

I also updated the names in my code, but thought that the negative of the current names might be better, as in, We are validating when something IsTrue, instead of when a condition IsFalse. Hence, I turned IsTrue into IsFalse and NulOrEmpty into IsNotNullOrEmpty, etc.
Just my 10c.
Thanks again.

[dustindavis]

I suppose the language can be changed to support/enhance readability of your code base. I intended it to be read as

1. Examine this model
2. Here are a list of conditions I want to check for
3. When one or more of the defined conditions occurs, the model is not valid

I think that the api could have additional syntax to improve readability. Care to add to it?