#Wise , 12 bytes (non-competing)

Mistah Figgins has me beat here

[:??:?^?&<]|

I just made this language so I thought I would try the basics.

Try it online

##Explanation

[ ... ] #Loop until our carry is zero
 : #Duplicate the top
 ?? #Roll the top two to the bottom
 : #Duplicate the top
 ? #Roll to the bottom

At this point we have n m m n on the stack

 ^ #Xor n and m
 ? #Roll that to the bottom
 & #And n and m to create the carry over
 < #Bitshift to the left
 | #Remove the extra zero with an or

Wise , 12 bytes (non-competing)

Mistah Figgins has me beat here

[:??:?^?&<]|

I just made this language so I thought I would try the basics.

Try it online

Explanation

[ ... ] #Loop until our carry is zero
 : #Duplicate the top
 ?? #Roll the top two to the bottom
 : #Duplicate the top
 ? #Roll to the bottom

At this point we have n m m n on the stack

 ^ #Xor n and m
 ? #Roll that to the bottom
 & #And n and m to create the carry over
 < #Bitshift to the left
 | #Remove the extra zero with an or

#Wise, 12 bytes (non-competing)

Mistah Figgins has me beat here

[:??:?^?&<]|

I just made this language so I thought I would try the basics.

Try it online

##Explanation

[ ... ] #Loop until our carry is zero
 : #Duplicate the top
 ?? #Roll the top two to the bottom
 : #Duplicate the top
 ? #Roll to the bottom

At this point we have n m m n on the stack

 ^ #Xor n and m
 ? #Roll that to the bottom
 & #And n and m to create the carry over
 < #Bitshift to the left
 | #Remove the extra zero with an or

#Wise, 12 bytes (non-competing)

Mistah Figgins has me beat here

[:??:?^?&<]|

I just made this language so I thought I would try the basics.

Try it online

##Explanation

[ ... ] #Loop until our carry is zero
 : #Duplicate the top
 ?? #Roll the top two to the bottom
 : #Duplicate the top
 ? #Roll to the bottom

At this point we have n m m n on the stack

 ^ #Xor n and m
 ? #Roll that to the bottom
 & #And n and m to create the carry over
 < #Bitshift to the left
 | #Remove the extra zero with an or

#Wise, 12 bytes (non-competing)

[:??:?^?&<]|

I just made this language so I thought I would try the basics.

Try it online

##Explanation

[ ... ] #Loop until our carry is zero
 : #Duplicate the top
 ?? #Roll the top two to the bottom
 : #Duplicate the top
 ? #Roll to the bottom

At this point we have n m m n on the stack

 ^ #Xor n and m
 ? #Roll that to the bottom
 & #And n and m to create the carry over
 < #Bitshift to the left
 | #Remove the extra zero with an or

#Wise, 12 bytes (non-competing)

Mistah Figgins has me beat here

[:??:?^?&<]|

I just made this language so I thought I would try the basics.

Try it online

##Explanation

[ ... ] #Loop until our carry is zero
 : #Duplicate the top
 ?? #Roll the top two to the bottom
 : #Duplicate the top
 ? #Roll to the bottom

At this point we have n m m n on the stack

 ^ #Xor n and m
 ? #Roll that to the bottom
 & #And n and m to create the carry over
 < #Bitshift to the left
 | #Remove the extra zero with an or