Compute Lazily - Model checking What is meant by lazily computing online? For example, in context of synthesis, that uses model checking. 

http://www.cs.colostate.edu/~france/CS614/Readings/Readings2011/Model-checking-Survey-a21-jhala.pdf

The above paper also mentions the concept in page 21:29.

Thanks in advance
In computer science, "lazy" means "just in time": in other words, you defer doing a computation until the last possible moment (e.g., until when the output is needed).

In computer science, "online" means that you are processing a bunch of input in a streaming fashion.  For instance, you might be given a sequence of queries.  An online algorithm would immediately answer each query.  In contrast, an offline algorithm might wait until it has seen all the queries before answering any of them.