== sum ==
tailRecursive fun sum(x: Long, sum: Long): Long {
    if (x == 0.toLong()) return sum
    return sum(x - 1, sum + x)
}
---------------------
                                                                 <v0>: Long                     NEW: magic[FAKE_INITIALIZER](x: Long) -> <v0>            
                                                                 <v1>: Long                     NEW: magic[FAKE_INITIALIZER](sum: Long) -> <v1>          
x                                                                <v2>: OR{{<: Any}, {<: Any}}   NEW: r(x) -> <v2>                                        
0                                                                <v3>: {<: Number}              NEW: r(0) -> <v3>                                        
toLong()                                                         <v4>: *                        NEW: call(toLong(), toLong|<v3>) -> <v4>                 
0.toLong()                                                       <v4>: *                        COPY                                                     
x == 0.toLong()                                                  <v5>: Boolean                  NEW: call(x == 0.toLong(), equals|<v2>, <v4>) -> <v5>    
sum                                                              <v6>: Long                     NEW: r(sum) -> <v6>                                      
return sum                                                       !<v7>: *                                                                                
if (x == 0.toLong()) return sum                                  <v8>: *                        NEW: merge(if (x == 0.toLong()) return sum|!<v7>) -> <v8>
x                                                                <v9>: Long                     NEW: r(x) -> <v9>                                        
1                                                                <v10>: Int                     NEW: r(1) -> <v10>                                       
x - 1                                                            <v11>: Long                    NEW: call(x - 1, minus|<v9>, <v10>) -> <v11>             
sum                                                              <v12>: Long                    NEW: r(sum) -> <v12>                                     
x                                                                <v13>: Long                    NEW: r(x) -> <v13>                                       
sum + x                                                          <v14>: Long                    NEW: call(sum + x, plus|<v12>, <v13>) -> <v14>           
sum(x - 1, sum + x)                                              <v15>: Long                    NEW: call(sum(x - 1, sum + x), sum|<v11>, <v14>) -> <v15>
return sum(x - 1, sum + x)                                       !<v16>: *                                                                               
{ if (x == 0.toLong()) return sum return sum(x - 1, sum + x) }   !<v16>: *                      COPY                                                     
=====================