MakeBlock
********** source program **********
fn main () -> Int {
var Int: x = 2;
while (true)
{
if ((x == 0))
break;
else
x = (x - 1);

}

return x;

}
********** type checking **********
--- step exp Int --->
--- step exp Int --->
--- step exp Int --->

********** type checking complete **********
fn main () -> Int {
var Int: x = 2;
while (true)
{
if ((x == 0))
break;
else
x = (x - 1);

}

return x;
}
********** starting execution **********
********** initializing globals **********
--- step exp () --->
********** calling main function **********
{
stack: top{main()<-1>}
heap: fun<main>, 
env: main: fun<main>, 
}
--- step exp main() --->
{
stack: top{main<-1> :: main()<0>}
heap: fun<main>, 
env: main: fun<main>, 
}
--- step exp main --->
{
stack: top{fun<main><-1> :: main()<0>}
heap: fun<main>, 
env: main: fun<main>, 
}
--- handle value fun<main> with main()<1>(fun<main>,) --->
{
stack: top{()<-1> :: main()<1>(fun<main>,)}
heap: fun<main>, 
env: main: fun<main>, 
}
--- step exp () --->
{
stack: top{()<-1> :: main()<1>(fun<main>,)}
heap: fun<main>, 
env: main: fun<main>, 
}
--- handle value () with main()<2>(fun<main>,(),) --->
pattern_match((), ())
{
stack: main{var Int: x = 2; ... <-1>} :: top{}
heap: fun<main>, 
env: main: fun<main>, 
}
--- step stmt var Int: x = 2; ...  --->
{
stack: main{var Int: x = 2;<-1> :: while (true)
 ...  ... <-1>} :: top{}
heap: fun<main>, 
env: main: fun<main>, 
}
--- step stmt var Int: x = 2; --->
{
stack: main{2<-1> :: var Int: x = 2;<0> :: while (true)
 ...  ... <-1>} :: top{}
heap: fun<main>, 
env: main: fun<main>, 
}
--- step exp 2 --->
{
stack: main{2<-1> :: var Int: x = 2;<0> :: while (true)
 ...  ... <-1>} :: top{}
heap: fun<main>, 
env: main: fun<main>, 
}
--- handle value 2 with var Int: x = 2;<1>(2,) --->
{
stack: main{Int: x<-1> :: var Int: x = 2;<1>(2,) :: while (true)
 ...  ... <-1>} :: top{}
heap: fun<main>, 
env: main: fun<main>, 
}
--- step exp Int: x --->
{
stack: main{Int<-1> :: Int: x<0> :: var Int: x = 2;<1>(2,) :: while (true)
 ...  ... <-1>} :: top{}
heap: fun<main>, 
env: main: fun<main>, 
}
--- step exp Int --->
{
stack: main{Int<-1> :: Int: x<0> :: var Int: x = 2;<1>(2,) :: while (true)
 ...  ... <-1>} :: top{}
heap: fun<main>, 
env: main: fun<main>, 
}
--- handle value Int with Int: x<1>(Int,) --->
{
stack: main{Int: x<-1> :: var Int: x = 2;<1>(2,) :: while (true)
 ...  ... <-1>} :: top{}
heap: fun<main>, 
env: main: fun<main>, 
}
--- handle value Int: x with var Int: x = 2;<2>(2,Int: x,) --->
pattern_match(Int: x, 2)
{
stack: main{while (true)
 ...  ... <-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- step stmt while (true)
 ...  ...  --->
{
stack: main{while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- step stmt while (true)
 ...  --->
{
stack: main{true<-1> :: while (true)
 ... <0> :: return x;<-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- step exp true --->
{
stack: main{true<-1> :: while (true)
 ... <0> :: return x;<-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- handle value true with while (true)
 ... <1>(true,) --->
{
stack: main{{
 ... 
}
<-1> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- step stmt {
 ... 
}
 --->
{
stack: main{if ((x == 0))
 ... 
else
 ... <-1> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- step stmt if ((x == 0))
 ... 
else
 ...  --->
{
stack: main{if ((x == 0))
 ... 
else
 ... <-1> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- step stmt if ((x == 0))
 ... 
else
 ...  --->
{
stack: main{(x == 0)<-1> :: if ((x == 0))
 ... 
else
 ... <0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- step exp (x == 0) --->
{
stack: main{x<-1> :: (x == 0)<0> :: if ((x == 0))
 ... 
else
 ... <0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- step exp x --->
{
stack: main{2<-1> :: (x == 0)<0> :: if ((x == 0))
 ... 
else
 ... <0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- handle value 2 with (x == 0)<1>(2,) --->
{
stack: main{0<-1> :: (x == 0)<1>(2,) :: if ((x == 0))
 ... 
else
 ... <0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- step exp 0 --->
{
stack: main{0<-1> :: (x == 0)<1>(2,) :: if ((x == 0))
 ... 
else
 ... <0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- handle value 0 with (x == 0)<2>(2,0,) --->
{
stack: main{false<-1> :: if ((x == 0))
 ... 
else
 ... <0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- handle value false with if ((x == 0))
 ... 
else
 ... <1>(false,) --->
{
stack: main{x = (x - 1);<-1> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- step stmt x = (x - 1); --->
{
stack: main{x<-1> :: x = (x - 1);<0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- step lvalue x --->
{
stack: main{ptr<1><-1> :: x = (x - 1);<0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- handle value ptr<1> with x = (x - 1);<1>(ptr<1>,) --->
{
stack: main{(x - 1)<-1> :: x = (x - 1);<1>(ptr<1>,) :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- step exp (x - 1) --->
{
stack: main{x<-1> :: (x - 1)<0> :: x = (x - 1);<1>(ptr<1>,) :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- step exp x --->
{
stack: main{2<-1> :: (x - 1)<0> :: x = (x - 1);<1>(ptr<1>,) :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- handle value 2 with (x - 1)<1>(2,) --->
{
stack: main{1<-1> :: (x - 1)<1>(2,) :: x = (x - 1);<1>(ptr<1>,) :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- step exp 1 --->
{
stack: main{1<-1> :: (x - 1)<1>(2,) :: x = (x - 1);<1>(ptr<1>,) :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- handle value 1 with (x - 1)<2>(2,1,) --->
{
stack: main{1<-1> :: x = (x - 1);<1>(ptr<1>,) :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 2, 
env: x: 2, main: fun<main>, 
}
--- handle value 1 with x = (x - 1);<2>(ptr<1>,1,) --->
{
stack: main{{
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- step stmt {
 ... 
}
 --->
{
stack: main{while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- step stmt while (true)
 ...  --->
{
stack: main{true<-1> :: while (true)
 ... <0> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- step exp true --->
{
stack: main{true<-1> :: while (true)
 ... <0> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- handle value true with while (true)
 ... <1>(true,) --->
{
stack: main{{
 ... 
}
<-1> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- step stmt {
 ... 
}
 --->
{
stack: main{if ((x == 0))
 ... 
else
 ... <-1> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- step stmt if ((x == 0))
 ... 
else
 ...  --->
{
stack: main{if ((x == 0))
 ... 
else
 ... <-1> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- step stmt if ((x == 0))
 ... 
else
 ...  --->
{
stack: main{(x == 0)<-1> :: if ((x == 0))
 ... 
else
 ... <0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- step exp (x == 0) --->
{
stack: main{x<-1> :: (x == 0)<0> :: if ((x == 0))
 ... 
else
 ... <0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- step exp x --->
{
stack: main{1<-1> :: (x == 0)<0> :: if ((x == 0))
 ... 
else
 ... <0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- handle value 1 with (x == 0)<1>(1,) --->
{
stack: main{0<-1> :: (x == 0)<1>(1,) :: if ((x == 0))
 ... 
else
 ... <0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- step exp 0 --->
{
stack: main{0<-1> :: (x == 0)<1>(1,) :: if ((x == 0))
 ... 
else
 ... <0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- handle value 0 with (x == 0)<2>(1,0,) --->
{
stack: main{false<-1> :: if ((x == 0))
 ... 
else
 ... <0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- handle value false with if ((x == 0))
 ... 
else
 ... <1>(false,) --->
{
stack: main{x = (x - 1);<-1> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- step stmt x = (x - 1); --->
{
stack: main{x<-1> :: x = (x - 1);<0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- step lvalue x --->
{
stack: main{ptr<1><-1> :: x = (x - 1);<0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- handle value ptr<1> with x = (x - 1);<1>(ptr<1>,) --->
{
stack: main{(x - 1)<-1> :: x = (x - 1);<1>(ptr<1>,) :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- step exp (x - 1) --->
{
stack: main{x<-1> :: (x - 1)<0> :: x = (x - 1);<1>(ptr<1>,) :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- step exp x --->
{
stack: main{1<-1> :: (x - 1)<0> :: x = (x - 1);<1>(ptr<1>,) :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- handle value 1 with (x - 1)<1>(1,) --->
{
stack: main{1<-1> :: (x - 1)<1>(1,) :: x = (x - 1);<1>(ptr<1>,) :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- step exp 1 --->
{
stack: main{1<-1> :: (x - 1)<1>(1,) :: x = (x - 1);<1>(ptr<1>,) :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- handle value 1 with (x - 1)<2>(1,1,) --->
{
stack: main{0<-1> :: x = (x - 1);<1>(ptr<1>,) :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 1, 
env: x: 1, main: fun<main>, 
}
--- handle value 0 with x = (x - 1);<2>(ptr<1>,0,) --->
{
stack: main{{
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 0, 
env: x: 0, main: fun<main>, 
}
--- step stmt {
 ... 
}
 --->
{
stack: main{while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 0, 
env: x: 0, main: fun<main>, 
}
--- step stmt while (true)
 ...  --->
{
stack: main{true<-1> :: while (true)
 ... <0> :: return x;<-1>} :: top{}
heap: fun<main>, 0, 
env: x: 0, main: fun<main>, 
}
--- step exp true --->
{
stack: main{true<-1> :: while (true)
 ... <0> :: return x;<-1>} :: top{}
heap: fun<main>, 0, 
env: x: 0, main: fun<main>, 
}
--- handle value true with while (true)
 ... <1>(true,) --->
{
stack: main{{
 ... 
}
<-1> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 0, 
env: x: 0, main: fun<main>, 
}
--- step stmt {
 ... 
}
 --->
{
stack: main{if ((x == 0))
 ... 
else
 ... <-1> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 0, 
env: x: 0, main: fun<main>, 
}
--- step stmt if ((x == 0))
 ... 
else
 ...  --->
{
stack: main{if ((x == 0))
 ... 
else
 ... <-1> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 0, 
env: x: 0, main: fun<main>, 
}
--- step stmt if ((x == 0))
 ... 
else
 ...  --->
{
stack: main{(x == 0)<-1> :: if ((x == 0))
 ... 
else
 ... <0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 0, 
env: x: 0, main: fun<main>, 
}
--- step exp (x == 0) --->
{
stack: main{x<-1> :: (x == 0)<0> :: if ((x == 0))
 ... 
else
 ... <0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 0, 
env: x: 0, main: fun<main>, 
}
--- step exp x --->
{
stack: main{0<-1> :: (x == 0)<0> :: if ((x == 0))
 ... 
else
 ... <0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 0, 
env: x: 0, main: fun<main>, 
}
--- handle value 0 with (x == 0)<1>(0,) --->
{
stack: main{0<-1> :: (x == 0)<1>(0,) :: if ((x == 0))
 ... 
else
 ... <0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 0, 
env: x: 0, main: fun<main>, 
}
--- step exp 0 --->
{
stack: main{0<-1> :: (x == 0)<1>(0,) :: if ((x == 0))
 ... 
else
 ... <0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 0, 
env: x: 0, main: fun<main>, 
}
--- handle value 0 with (x == 0)<2>(0,0,) --->
{
stack: main{true<-1> :: if ((x == 0))
 ... 
else
 ... <0> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 0, 
env: x: 0, main: fun<main>, 
}
--- handle value true with if ((x == 0))
 ... 
else
 ... <1>(true,) --->
{
stack: main{break;<-1> :: {
 ... 
}
<0> :: while (true)
 ... <-1> :: return x;<-1>} :: top{}
heap: fun<main>, 0, 
env: x: 0, main: fun<main>, 
}
--- step stmt break; --->
{
stack: main{return x;<-1>} :: top{}
heap: fun<main>, 0, 
env: x: 0, main: fun<main>, 
}
--- step stmt return x; --->
{
stack: main{x<-1> :: return x;<0>} :: top{}
heap: fun<main>, 0, 
env: x: 0, main: fun<main>, 
}
--- step exp x --->
{
stack: main{0<-1> :: return x;<0>} :: top{}
heap: fun<main>, 0, 
env: x: 0, main: fun<main>, 
}
--- handle value 0 with return x;<1>(0,) --->
{
stack: top{0<-1>}
heap: fun<main>, !!0, 
env: main: fun<main>, 
}
result: 0