move call to log into showI
initial attempt at adding call-by-name semantics with update markers
output newline after log line instead of before
put newline after log instead of before
move incrementing r outside of newC
add rule to test optimization
replace pointer manipulation with call to pop
include primes in test_opt
replace assert with logp
working call-by-need but leaks due to not decrementing reference count
add a second test for opt
bug if not in decrement reference of marker->e, it is in not incrementing marker->e->e
move incrementing reference count into newC
add one more level of interpretation to test_uni and test_opt2