Fix the semantics of introducing with empty intro patterns.
Fix the semantics of introducing with empty intro patterns.

JasonGross/coq,Matafou/coq,Zimmi48/coq,JasonGross/coq,ejgallego/coq,Zimmi48/coq,Matafou/coq,SkySkimmer/coq,silene/coq,gares/coq,JasonGross/coq,silene/coq,JasonGross/coq,Zimmi48/coq,ejgallego/coq,Zimmi48/coq,SkySkimmer/coq,SkySkimmer/coq,gares/coq,coq/coq,coq/coq,gares/coq,coq/coq,Matafou/coq,SkySkimmer/coq,silene/coq,ejgallego/coq,coq/coq,gares/coq,ejgallego/coq,gares/coq