ᴹ✶[t+t], [d+d] from suffixion became [st], [zd]; [{ttʰd}+t|d+d] > [st|zd]

ᴹ✶[t+t], [d+d] from suffixion became [st], [zd]; [{ttʰd}+t|d+d] > [st|zd]
GS/§4.7 GS/§4.8 GS/§4.9 WGHC/§87ii [PIE tt > tˢt > Germ/It/Kelt ss] WGHC/§91ii [PIE dd, td > dᶻd > Kelt zd] @@@

References ✧ PE18/41-42, 54, 65; PE19/39

Phonetic Rule Elements

[t+t] > [st] ✧ PE19/51 (t-t > st; older)
[tʰ+t] > [st]
[d+t] > [st]
[d+d] > [zd] ✧ PE19/51 (d-d > zd)

Phonetic Rule Examples

reddā > rezdā d+d > zd ᴹ✶reddā/red-tā > ᴹQ. resta ✧ EtyAC/RED
reddā > rezdā d+d > zd ᴹ✶reddā/red-tā > N. rîð ✧ EtyAC/RED
ledta- > lesta- d+t > st ᴹ√ELED > ᴹQ. lesta- ✧ Ety/ELED
rodta- > rosta- d+t > st ᴹ√ROD > ON. rostóbe ✧ Ety/ROD
sjadta > sjasta d+t > st ᴹ✶syad-ta > N. hast ✧ Ety/SYAD
wedtā > westā d+t > st ᴹ✶wed-tā > ᴹQ. vesta ✧ Ety/WED
wedta- > westa- d+t > st ᴹ✶wed-tā > ᴹQ. vesta- ✧ Ety/WED
wedtā > westā d+t > st ᴹ✶wed-tā > N. gwest ✧ Ety/WED
wedta- > westa- d+t > st ᴹ✶wed-tā > N. gwesto ✧ Ety/WED
kotta > kosta t+t > st ᴹ✶kot-t- > ᴹQ. kosta- ✧ Ety/KOT
kotte > koste t+t > st ᴹ✶kot-t- > N. cost ✧ Ety/KOT
kʰotʰta > kʰosta tʰ+t > st ᴹ√KHOTH > ᴹQ. hosta ✧ Ety/KHOTH
kʰotʰta- > kʰosta- tʰ+t > st ᴹ√KHOTH > ᴹQ. hosta- ✧ Ety/KHOTH
kʰotʰta > kʰosta tʰ+t > st ᴹ√KHOTH > N. host ✧ Ety/KHOTH