User talk:Sophivorus/Causality

Primitives
Let $$Ex$$ be a one-place predicate with intended reading '$$x$$ is an event'.

Let $$xCy$$ be a two-place predicate with intended reading '$$x$$ is a cause of $$y$$'.

Let $$b$$ be a name with intended reading 'the Big Bang'.

Definitions
Event $$x$$ is an effect of event $$y$$ iff $$y$$ is a cause of $$x$$.

Event $$x$$ is a direct cause of event $$y$$ iff there is no event $$z$$, such that $$xCz$$ and $$zCy$$.

Axioms

 * 1) The Big Bang is an event.
 * 2) Every event different from the Big Bang has at least one cause.
 * 3) If event $$x$$ is a cause of event $$y$$, then $$y$$ is not a cause of $$x$$.
 * 4) If event $$x$$ is a cause of event $$y$$, and $$y$$ is a cause of event $$z$$, then $$x$$ is a cause of $$z$$.