cases i'
case rtr
α : Type
inst✝ : Hierarchical α
rtr : α
i : ID
rtr' : Component.type α Component.rtr
h : rtr{Component.rtr}{i} = some rtr'
i' : Component.idType Component.rtr
o : Component.type (Component.type α Component.rtr) Component.rtr
ho : rtr'[Component.rtr][i'] = some o
⊢ ∃ j, rtr[Component.rtr][j] = some o
case rtr.none
α : Type
inst✝ : Hierarchical α
rtr : α
i : ID
rtr' : Component.type α Component.rtr
h : rtr{Component.rtr}{i} = some rtr'
o : Component.type (Component.type α Component.rtr) Component.rtr
ho : rtr'[Component.rtr][none] = some o
⊢ ∃ j, rtr[Component.rtr][j] = some o

case rtr.some
α : Type
inst✝ : Hierarchical α
rtr : α
i : ID
rtr' : Component.type α Component.rtr
h : rtr{Component.rtr}{i} = some rtr'
o : Component.type (Component.type α Component.rtr) Component.rtr
val✝ : ID
ho : rtr'[Component.rtr][some val✝] = some o
⊢ ∃ j, rtr[Component.rtr][j] = some o