UWN

But only with ``` ?- set_prolog_flag(occurs_check,true). true. ?- test(E,call). % CPU time: 0.475s, 3 inferences E = 2^18 ; % CPU time: 0.646s, 54 inferences E = 2^19 ; %...

Closable.

It seems that there is also another somewhat related error: ``` $ ulimit -v 250000; target/release/scryer-prolog -f ?- use_module(library(between)). true. ?- between(1,65000,I), I < 0. false. % thus, it works...

Current reproduction: ``` ulrich@TU-Wien:/opt/gupu/scryer-prolog$ ulimit -v 70000 ulrich@TU-Wien:/opt/gupu/scryer-prolog$ target/release/scryer-prolog -f ?- use_module(library(between)). true. ?- between(1,2000000,I),I

If this leftover choice point intended? ``` ?- v(B,C,D)=v(-2,-1,-2), [B,C,D]ins-2..0,0#==>B#>C/D. B = -2, C = -1, D = -2 ; false. % unexpected leftover choice point ```

Ah, looks like #1028.

Please do not forget this. Here is another such unexpected residuum: ``` ?- set_prolog_flag(occurs_check, true). true. ?- X = Y, dif(X,f(Y)). X = Y. ?- dif(X,f(Y)), X = Y. X...

How has this been solved? It seems that only the projection removes the redundant goal. That is, the dif/2 goals persist, but are at the end removed superficially. Right? Consider:...

Maybe consider [this approach](https://github.com/mthom/scryer-prolog/issues/135#issuecomment-488348886).

``` ?- dif(0-B,A-C),+_=A,+1=A,C=c. A = +1, C = c, dif:dif(0-B,+1-c), unexpected. ```