notation "(a \sup b)" left associative with precedence 60 for @{ 'exp $a $b}.
notation "s \sup (-1)" with precedence 60 for @{ 'invert $s }.
notation < "s \sup (-1) x" with precedence 60 for @{ 'invert_appl $s $x}.
notation "(a \sup b)" left associative with precedence 60 for @{ 'exp $a $b}.
notation "s \sup (-1)" with precedence 60 for @{ 'invert $s }.
notation < "s \sup (-1) x" with precedence 60 for @{ 'invert_appl $s $x}.