Lean4
/-- `s(x, y)` is an unordered pair,
which is to say a pair modulo the action of the symmetric group.
It is equal to `Sym2.mk (x, y)`. -/
@[term_parser 1000]
public meta def «termS(_,_)» : Lean.ParserDescr✝ :=
ParserDescr.node✝ `«termS(_,_)» 1024
(ParserDescr.binary✝ `andthen
(ParserDescr.binary✝ `andthen
(ParserDescr.binary✝ `andthen
(ParserDescr.binary✝ `andthen (ParserDescr.symbol✝ "s(") (ParserDescr.cat✝ `term 0))
(ParserDescr.symbol✝ ", "))
(ParserDescr.cat✝ `term 0))
(ParserDescr.symbol✝ ")"))