---input---
_op_←{_←⍺ ⍵⋄(⍺⍺ ⍺)+⍵⍵ ⍵}

---tokens---
'_op_'        Name.Variable
'←'           Keyword.Declaration
'{'           Keyword.Type
'_'           Name.Variable
'←'           Keyword.Declaration
'⍺'           Name.Builtin.Pseudo
' '           Text.Whitespace
'⍵'           Name.Builtin.Pseudo
'⋄'           Punctuation
'('           Punctuation
'⍺'           Name.Builtin.Pseudo
'⍺'           Name.Builtin.Pseudo
' '           Text.Whitespace
'⍺'           Name.Builtin.Pseudo
')'           Punctuation
'+'           Operator
'⍵'           Name.Builtin.Pseudo
'⍵'           Name.Builtin.Pseudo
' '           Text.Whitespace
'⍵'           Name.Builtin.Pseudo
'}'           Keyword.Type
'\n'          Text.Whitespace