********** source program **********
fn main () -> Int {
var (x = Int, y = Int): t2 = (y = 5, x = 2);
t2.y = 3;
return ((t2.y - t2.x) - 1);

}
********** type checking **********
--- step exp Int --->
--- step exp Int --->
--- step exp (x = Int, y = Int) --->
--- step exp Int --->
--- handle value Int with (x = Int, y = Int)<1>(Int,) --->
--- step exp Int --->
--- handle value Int with (x = Int, y = Int)<2>(Int,Int,) --->

********** type checking complete **********
fn main () -> Int {
var (x = Int, y = Int): t2 = (y = 5, x = 2);
t2.y = 3;
return ((t2.y - t2.x) - 1);
}
********** 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 (x = Int, y = Int): t2 = (y = 5, x = 2); ... <-1>} :: top{}
heap: fun<main>, 
env: main: fun<main>, 
}
--- step stmt var (x = Int, y = Int): t2 = (y = 5, x = 2); ...  --->
{
stack: main{var (x = Int, y = Int): t2 = (y = 5, x = 2);<-1> :: t2.y = 3; ... <-1>} :: top{}
heap: fun<main>, 
env: main: fun<main>, 
}
--- step stmt var (x = Int, y = Int): t2 = (y = 5, x = 2); --->
{
stack: main{(y = 5, x = 2)<-1> :: var (x = Int, y = Int): t2 = (y = 5, x = 2);<0> :: t2.y = 3; ... <-1>} :: top{}
heap: fun<main>, 
env: main: fun<main>, 
}
--- step exp (y = 5, x = 2) --->
{
stack: main{5<-1> :: (y = 5, x = 2)<0> :: var (x = Int, y = Int): t2 = (y = 5, x = 2);<0> :: t2.y = 3; ... <-1>} :: top{}
heap: fun<main>, 
env: main: fun<main>, 
}
--- step exp 5 --->
{
stack: main{5<-1> :: (y = 5, x = 2)<0> :: var (x = Int, y = Int): t2 = (y = 5, x = 2);<0> :: t2.y = 3; ... <-1>} :: top{}
heap: fun<main>, 
env: main: fun<main>, 
}
--- handle value 5 with (y = 5, x = 2)<1>(5,) --->
{
stack: main{2<-1> :: (y = 5, x = 2)<1>(5,) :: var (x = Int, y = Int): t2 = (y = 5, x = 2);<0> :: t2.y = 3; ... <-1>} :: top{}
heap: fun<main>, 
env: main: fun<main>, 
}
--- step exp 2 --->
{
stack: main{2<-1> :: (y = 5, x = 2)<1>(5,) :: var (x = Int, y = Int): t2 = (y = 5, x = 2);<0> :: t2.y = 3; ... <-1>} :: top{}
heap: fun<main>, 
env: main: fun<main>, 
}
--- handle value 2 with (y = 5, x = 2)<2>(5,2,) --->
{
stack: main{(y = 5@1, x = 2@2)<-1> :: var (x = Int, y = Int): t2 = (y = 5, x = 2);<0> :: t2.y = 3; ... <-1>} :: top{}
heap: fun<main>, 5, 2, 
env: main: fun<main>, 
}
--- handle value (y = 5@1, x = 2@2) with var (x = Int, y = Int): t2 = (y = 5, x = 2);<1>((y = 5@1, x = 2@2),) --->
{
stack: main{(x = Int, y = Int): t2<-1> :: var (x = Int, y = Int): t2 = (y = 5, x = 2);<1>((y = 5@1, x = 2@2),) :: t2.y = 3; ... <-1>} :: top{}
heap: fun<main>, 5, 2, 
env: main: fun<main>, 
}
--- step exp (x = Int, y = Int): t2 --->
{
stack: main{(x = Int, y = Int)<-1> :: (x = Int, y = Int): t2<0> :: var (x = Int, y = Int): t2 = (y = 5, x = 2);<1>((y = 5@1, x = 2@2),) :: t2.y = 3; ... <-1>} :: top{}
heap: fun<main>, 5, 2, 
env: main: fun<main>, 
}
--- step exp (x = Int, y = Int) --->
{
stack: main{Int<-1> :: (x = Int, y = Int)<0> :: (x = Int, y = Int): t2<0> :: var (x = Int, y = Int): t2 = (y = 5, x = 2);<1>((y = 5@1, x = 2@2),) :: t2.y = 3; ... <-1>} :: top{}
heap: fun<main>, 5, 2, 
env: main: fun<main>, 
}
--- step exp Int --->
{
stack: main{Int<-1> :: (x = Int, y = Int)<0> :: (x = Int, y = Int): t2<0> :: var (x = Int, y = Int): t2 = (y = 5, x = 2);<1>((y = 5@1, x = 2@2),) :: t2.y = 3; ... <-1>} :: top{}
heap: fun<main>, 5, 2, 
env: main: fun<main>, 
}
--- handle value Int with (x = Int, y = Int)<1>(Int,) --->
{
stack: main{Int<-1> :: (x = Int, y = Int)<1>(Int,) :: (x = Int, y = Int): t2<0> :: var (x = Int, y = Int): t2 = (y = 5, x = 2);<1>((y = 5@1, x = 2@2),) :: t2.y = 3; ... <-1>} :: top{}
heap: fun<main>, 5, 2, 
env: main: fun<main>, 
}
--- step exp Int --->
{
stack: main{Int<-1> :: (x = Int, y = Int)<1>(Int,) :: (x = Int, y = Int): t2<0> :: var (x = Int, y = Int): t2 = (y = 5, x = 2);<1>((y = 5@1, x = 2@2),) :: t2.y = 3; ... <-1>} :: top{}
heap: fun<main>, 5, 2, 
env: main: fun<main>, 
}
--- handle value Int with (x = Int, y = Int)<2>(Int,Int,) --->
{
stack: main{(x = Int@3, y = Int@4)<-1> :: (x = Int, y = Int): t2<0> :: var (x = Int, y = Int): t2 = (y = 5, x = 2);<1>((y = 5@1, x = 2@2),) :: t2.y = 3; ... <-1>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 
env: main: fun<main>, 
}
--- handle value (x = Int@3, y = Int@4) with (x = Int, y = Int): t2<1>((x = Int@3, y = Int@4),) --->
{
stack: main{(x = Int@3, y = Int@4): t2<-1> :: var (x = Int, y = Int): t2 = (y = 5, x = 2);<1>((y = 5@1, x = 2@2),) :: t2.y = 3; ... <-1>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 
env: main: fun<main>, 
}
--- handle value (x = Int@3, y = Int@4): t2 with var (x = Int, y = Int): t2 = (y = 5, x = 2);<2>((y = 5@1, x = 2@2),(x = Int@3, y = Int@4): t2,) --->
pattern_match((x = Int@3, y = Int@4): t2, (y = 5@1, x = 2@2))
{
stack: main{t2.y = 3; ... <-1>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 5, 2, (y = 5@5, x = 2@6), 
env: t2: (y = 5@5, x = 2@6), main: fun<main>, 
}
--- step stmt t2.y = 3; ...  --->
{
stack: main{t2.y = 3;<-1> :: return ((t2.y - t2.x) - 1);<-1>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 5, 2, (y = 5@5, x = 2@6), 
env: t2: (y = 5@5, x = 2@6), main: fun<main>, 
}
--- step stmt t2.y = 3; --->
{
stack: main{t2.y<-1> :: t2.y = 3;<0> :: return ((t2.y - t2.x) - 1);<-1>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 5, 2, (y = 5@5, x = 2@6), 
env: t2: (y = 5@5, x = 2@6), main: fun<main>, 
}
--- step lvalue t2.y --->
{
stack: main{t2<-1> :: t2.y<0> :: t2.y = 3;<0> :: return ((t2.y - t2.x) - 1);<-1>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 5, 2, (y = 5@5, x = 2@6), 
env: t2: (y = 5@5, x = 2@6), main: fun<main>, 
}
--- step lvalue t2 --->
{
stack: main{ptr<7><-1> :: t2.y<0> :: t2.y = 3;<0> :: return ((t2.y - t2.x) - 1);<-1>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 5, 2, (y = 5@5, x = 2@6), 
env: t2: (y = 5@5, x = 2@6), main: fun<main>, 
}
--- handle value ptr<7> with t2.y<1>(ptr<7>,) --->
{
stack: main{ptr<5><-1> :: t2.y = 3;<0> :: return ((t2.y - t2.x) - 1);<-1>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 5, 2, (y = 5@5, x = 2@6), 
env: t2: (y = 5@5, x = 2@6), main: fun<main>, 
}
--- handle value ptr<5> with t2.y = 3;<1>(ptr<5>,) --->
{
stack: main{3<-1> :: t2.y = 3;<1>(ptr<5>,) :: return ((t2.y - t2.x) - 1);<-1>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 5, 2, (y = 5@5, x = 2@6), 
env: t2: (y = 5@5, x = 2@6), main: fun<main>, 
}
--- step exp 3 --->
{
stack: main{3<-1> :: t2.y = 3;<1>(ptr<5>,) :: return ((t2.y - t2.x) - 1);<-1>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 5, 2, (y = 5@5, x = 2@6), 
env: t2: (y = 5@5, x = 2@6), main: fun<main>, 
}
--- handle value 3 with t2.y = 3;<2>(ptr<5>,3,) --->
{
stack: main{return ((t2.y - t2.x) - 1);<-1>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 3, 2, (y = 3@5, x = 2@6), 
env: t2: (y = 3@5, x = 2@6), main: fun<main>, 
}
--- step stmt return ((t2.y - t2.x) - 1); --->
{
stack: main{((t2.y - t2.x) - 1)<-1> :: return ((t2.y - t2.x) - 1);<0>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 3, 2, (y = 3@5, x = 2@6), 
env: t2: (y = 3@5, x = 2@6), main: fun<main>, 
}
--- step exp ((t2.y - t2.x) - 1) --->
{
stack: main{(t2.y - t2.x)<-1> :: ((t2.y - t2.x) - 1)<0> :: return ((t2.y - t2.x) - 1);<0>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 3, 2, (y = 3@5, x = 2@6), 
env: t2: (y = 3@5, x = 2@6), main: fun<main>, 
}
--- step exp (t2.y - t2.x) --->
{
stack: main{t2.y<-1> :: (t2.y - t2.x)<0> :: ((t2.y - t2.x) - 1)<0> :: return ((t2.y - t2.x) - 1);<0>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 3, 2, (y = 3@5, x = 2@6), 
env: t2: (y = 3@5, x = 2@6), main: fun<main>, 
}
--- step exp t2.y --->
{
stack: main{t2<-1> :: t2.y<0> :: (t2.y - t2.x)<0> :: ((t2.y - t2.x) - 1)<0> :: return ((t2.y - t2.x) - 1);<0>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 3, 2, (y = 3@5, x = 2@6), 
env: t2: (y = 3@5, x = 2@6), main: fun<main>, 
}
--- step lvalue t2 --->
{
stack: main{ptr<7><-1> :: t2.y<0> :: (t2.y - t2.x)<0> :: ((t2.y - t2.x) - 1)<0> :: return ((t2.y - t2.x) - 1);<0>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 3, 2, (y = 3@5, x = 2@6), 
env: t2: (y = 3@5, x = 2@6), main: fun<main>, 
}
--- handle value ptr<7> with t2.y<1>(ptr<7>,) --->
{
stack: main{3<-1> :: (t2.y - t2.x)<0> :: ((t2.y - t2.x) - 1)<0> :: return ((t2.y - t2.x) - 1);<0>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 3, 2, (y = 3@5, x = 2@6), 
env: t2: (y = 3@5, x = 2@6), main: fun<main>, 
}
--- handle value 3 with (t2.y - t2.x)<1>(3,) --->
{
stack: main{t2.x<-1> :: (t2.y - t2.x)<1>(3,) :: ((t2.y - t2.x) - 1)<0> :: return ((t2.y - t2.x) - 1);<0>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 3, 2, (y = 3@5, x = 2@6), 
env: t2: (y = 3@5, x = 2@6), main: fun<main>, 
}
--- step exp t2.x --->
{
stack: main{t2<-1> :: t2.x<0> :: (t2.y - t2.x)<1>(3,) :: ((t2.y - t2.x) - 1)<0> :: return ((t2.y - t2.x) - 1);<0>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 3, 2, (y = 3@5, x = 2@6), 
env: t2: (y = 3@5, x = 2@6), main: fun<main>, 
}
--- step lvalue t2 --->
{
stack: main{ptr<7><-1> :: t2.x<0> :: (t2.y - t2.x)<1>(3,) :: ((t2.y - t2.x) - 1)<0> :: return ((t2.y - t2.x) - 1);<0>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 3, 2, (y = 3@5, x = 2@6), 
env: t2: (y = 3@5, x = 2@6), main: fun<main>, 
}
--- handle value ptr<7> with t2.x<1>(ptr<7>,) --->
{
stack: main{2<-1> :: (t2.y - t2.x)<1>(3,) :: ((t2.y - t2.x) - 1)<0> :: return ((t2.y - t2.x) - 1);<0>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 3, 2, (y = 3@5, x = 2@6), 
env: t2: (y = 3@5, x = 2@6), main: fun<main>, 
}
--- handle value 2 with (t2.y - t2.x)<2>(3,2,) --->
{
stack: main{1<-1> :: ((t2.y - t2.x) - 1)<0> :: return ((t2.y - t2.x) - 1);<0>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 3, 2, (y = 3@5, x = 2@6), 
env: t2: (y = 3@5, x = 2@6), main: fun<main>, 
}
--- handle value 1 with ((t2.y - t2.x) - 1)<1>(1,) --->
{
stack: main{1<-1> :: ((t2.y - t2.x) - 1)<1>(1,) :: return ((t2.y - t2.x) - 1);<0>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 3, 2, (y = 3@5, x = 2@6), 
env: t2: (y = 3@5, x = 2@6), main: fun<main>, 
}
--- step exp 1 --->
{
stack: main{1<-1> :: ((t2.y - t2.x) - 1)<1>(1,) :: return ((t2.y - t2.x) - 1);<0>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 3, 2, (y = 3@5, x = 2@6), 
env: t2: (y = 3@5, x = 2@6), main: fun<main>, 
}
--- handle value 1 with ((t2.y - t2.x) - 1)<2>(1,1,) --->
{
stack: main{0<-1> :: return ((t2.y - t2.x) - 1);<0>} :: top{}
heap: fun<main>, 5, 2, Int, Int, 3, 2, (y = 3@5, x = 2@6), 
env: t2: (y = 3@5, x = 2@6), main: fun<main>, 
}
--- handle value 0 with return ((t2.y - t2.x) - 1);<1>(0,) --->
{
stack: top{0<-1>}
heap: fun<main>, 5, 2, Int, Int, !!3, !!2, !!(y = !!3@5, x = !!2@6), 
env: main: fun<main>, 
}
result: 0