How many nuclei participate in syngamy,triple fusion and double fertilisation respectively?

Angiosperms exhibit double fertilization because two fusion events occur in each embryo sac, namely syngamy and triple fusion. The products of these fusions are the diploid zygote and the triploid primary endosperm nucleus (in the primary endosperm cell).
Syngamy involves two nuclei.
Triple fusion involves 3 nuclei.
Since syngamy and triple fusion are together known as double fertilization, it includes 5 nuclei.