What is the difference between "implication", "implies", and 'if-else"?

In reply to dave_59:

Hello, Dave.

Thanks to your explanation. It helps to understand “implication statement” for me.

I have a question more. The standard document says

property_expr1 implies property_expr2
// A property of this form evaluates to true if, and only if, either property_expr1 evaluates to false or property_expr2 evaluates to true.

And, you explained that

However when the antecedent is a sequence or property, the consequent gets evaluated concurrently with the antecedent instead of waiting for the antecedent to become true.

Is the property true regardless of the outcome of the antecedent if the evaluation of the consequent is completed for true during the evaluation of the antecedent?
If the consequent is false in this case, is the property false?

Thanks always for your explanations and comments.