+ (binary) operator (x:String + y:String) -> String String concatenation. operator (x:String + y:Boolean) -> String String concatenation. operator (x:String + y:Real) -> String String concatenation. operator (x:String + y:Integer) -> String String concatenation. operator (x:String + y:Boolean[_]) -> String String concatenation. operator (x:String + y:Real[_]) -> String String concatenation. operator (x:String + y:Integer[_]) -> String String concatenation. operator (x:String + y:Boolean[_,_]) -> String String concatenation. operator (x:String + y:Real[_,_]) -> String String concatenation. operator (x:String + y:Integer[_,_]) -> String String concatenation. operator (x:Boolean + y:String) -> String String concatenation. operator (x:Real + y:String) -> String String concatenation. operator (x:Integer + y:String) -> String String concatenation. operator (x:Boolean[_] + y:String) -> String String concatenation. operator (x:Real[_] + y:String) -> String String concatenation. operator (x:Integer[_] + y:String) -> String String concatenation. operator (x:Boolean[_,_] + y:String) -> String String concatenation. operator (x:Real[_,_] + y:String) -> String String concatenation. operator (x:Integer[_,_] + y:String) -> String String concatenation. operator (x:NumberLike + y:NumberLike) -> NumberLike Element-wise addition.