Free variable applied in LHS

[GuillaumeGen]

For the file

nat : Type.
def pair : (nat->nat)->nat->nat.
def split : nat->nat.
[F,Y] split (F Y)-->pair F Y.

which should obviously be refused by Dedukti since F is a free variable applied in the left-hand side of a rule, the error message is:

ERROR line:4 column:15 The variable 'Y[0]' was not found in context:

which is not informative at all.

[francoisthire]

@Gaspi , any plan to solve this?