\b
\q1
\v=12
\v~=If you blow on a spark, it will burn; 
\¬q1
\q2
\p~<<q2=and if you spit upon it, it will be quenched. 
\¬q2
\q2
\p~<<q2=Both of these come out of your mouth. 
\¬q2
\¬v