+
+notation < "(❲i↹j❳)n"
+ right associative with precedence 71
+for @{ 'transposition $i $j $n}.
+
+notation < "(❲i \atop j❳)n"
+ right associative with precedence 71
+for @{ 'transposition $i $j $n}.
+
+interpretation "natural transposition" 'transposition i j n =
+ (cic:/matita/nat/permutation/transpose.con i j n).
+