lua.wetgenes.tardis.m4.sub
m4 = m4:sub(m4b)
m4 = m4:sub(m4b,r)
Subtract m4b this m4.
If r is provided then the result is written into r and returned otherwise m4 is modified and returned.
m4 = m4:sub(m4b)
m4 = m4:sub(m4b,r)
Subtract m4b this m4.
If r is provided then the result is written into r and returned otherwise m4 is modified and returned.