A (short) explanation of some internals

[Francisco Vila]

Hello,

I cannot find a simple explanation to this common behavior of time 
signatures and key signatures in simultanepus staves.

  "Time signatures entered in one staff affect all other staves by 
default. On the other hand, the key signature of one staff does not 
affect other staves. This different default behavior is because scores 
with transposing instruments are more common than polyrhythmic scores. "

I have searched a lot about contexts and engravers but I haven't found 
what's the mechanism this relies on, or where is it coded in the sources.

--
Francisco Vila, Ph.D. - Badajoz (Spain)
paconet.org , lilypond.es