Is it permissible to call "Abd Al-Rahman" "Rahman" without the definite article "Al," and is this considered disbelief?

The names of Allah Almighty are divided into two categories: The first is exclusive to Allah and it is impermissible to be named by them, such as "Ar-Rabb" (The Lord) and "Ar-Rahman" (The Most Merciful). Whoever names himself with them is promised a severe warning. Therefore, one should not address someone named "Abdus-Samad" as "Ya Samad" (O Self-Sufficient). As for the second category, it includes names that are not exclusive to Allah and may be applied to humans, such as "Sami'" (All-Hearing), "Basir" (All-Seeing), and "'Alim" (All-Knowing). Thus, it is permissible to call "Abdul-Karim" as "Karim" (Generous) if the intention is to address the person, and not the name of Allah. However, it is preferable to abandon all of that due to the possibility of misconception, and suffice with calling the person "Abd" (Servant) or abbreviating it, such as "Aboud."