Which example primarily involves elision rather than substitution or assimilation?

Weak-Initial Roots: Elision, Substitution, Assimilation and Short Paradigms

• يَوْعِدُ → يَعِدُ
• مِوْزَانٌ → مِيزَانٌ
• مُيْقِنٌ → مُوقِنٌ
• اِوْتَقَدَ → اِتَّقَدَ