Revert "refactoring: Reductionops.contextual_reduction_function type"
Revert "refactoring: Reductionops.contextual_reduction_function type"

This reverts commit 470d0d56467a3a587dc34f958ffea8259618d1ae.

ppedrot/coq,letouzey/coq-wip,maximedenes/coq,letouzey/coq-wip,Lionel-Rieg/coq,Matafou/coq,amintimany/coq,william-lawvere/coq,Lionel-Rieg/coq,amintimany/coq,ejgallego/coq,Zimmi48/coq,gares/coq,SkySkimmer/coq,coq/coq,Lionel-Rieg/coq,gares/coq,Zimmi48/coq,coq/coq,SkySkimmer/coq,silene/coq,gares/coq,ppedrot/coq,Zimmi48/coq,gares/coq,letouzey/coq-wip,william-lawvere/coq,ejgallego/coq,coq/coq,ejgallego/coq,william-lawvere/coq,silene/coq,JasonGross/coq,SkySkimmer/coq,ppedrot/coq,letouzey/coq-wip,ppedrot/coq,coq/coq,ppedrot/coq,maximedenes/coq,maximedenes/coq,maximedenes/coq,Zimmi48/coq,ejgallego/coq,SkySkimmer/coq,JasonGross/coq,silene/coq,JasonGross/coq,maximedenes/coq,gares/coq,letouzey/coq-wip,Matafou/coq,JasonGross/coq,Matafou/coq,amintimany/coq