Pattern elements:
1. 1st line-mover (usually an R) attacks 1st target with weight 1, defended once. (The target can be an empty square.)

2. 2nd line-mover (usually a B) attacks 2nd target with weight 1, defended once.

3. Move your Q onto the intersection of #1 and #2. This reduces to a simple fork, as if the R+B + both defenders were not present.

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As the Q must generally be behind the R and in front of the B, this further necessitates:

4. an R lift

5. a B thing (develop + retreat) or fianchetto

Astronomy: Epsilon Lyrae, an easy binocular/spotter scope double (208.2"), of which each "star" is itself a tight double (~2.5"). Splitting all 4 stars simultaneously (in the same field) is a canonical test of your optics and collimation.