Reviewed-by: gares
Ack-by: Janno
Ack-by: CohenCyril
Ack-by: Zimmi48
Ack-by: jfehrle
Ack-by: SkySkimmer

Ack-by: JasonGross
Reviewed-by: herbelin
Reviewed-by: jashug
Reviewed-by: jfehrle
Reviewed-by: ppedrot

This commit adds a more detailed explanation of what kinds of terms are
allowed in fields of a canonical instance, how the fields are used as
keys for canonical extension, what terms are considered overlapping, and
how Coq reacts to overlapping fields.

Reviewed-by: JasonGross
Ack-by: jfehrle

Reviewed-by: mattam82
Ack-by: Zimmi48

Reviewed-by: Zimmi48
Reviewed-by: vbgl

Reviewed-by: Zimmi48
Ack-by: cpitclaudel

Reviewed-by: Zimmi48
Ack-by: JasonGross