He would often assert that there was life on other planets.
To maintain or defend, as a cause or a claim, by words or measures; to vindicate a claim or title to
To insist on the legitimacy of one's rights, opinion, etc; not to allow oneself to be dismissed; to ensure that one is taken into consideration; to make oneself respected; to be assertive.
To use or exercise and thereby prove the existence of.
To set a signal on a line using a voltage or electric current.
To specify that a condition or expression is true at a certain point in the code.
To declare with assurance or plainly and strongly; to state positively.
an assertion; a section of source code which tests whether an expected condition is true.