This is the 10920th most frequent Turkish word.
değişmemeli
"Değişmemeli" means "should not change" in English.
Here, 'değişmemeli' implies a commitment or an agreement not to alter 'this matter' again.
Söz verdiğin gibi bu mesele bir daha değişmemeli.
This matter should not change again as you promised.
The word 'değişmemeli' here expresses a necessity or advice that the subject ('the rules we know to be correct') should not undergo change or modification.
Doğru olduklarını bildiğimiz kurallar değişmemeli.
The rules that we know to be correct should not change.
In this sentence, 'değişmemeli' suggests a value judgment or recommendation that 'our historical heritage' should remain as is.