Section SUBJECT_REDUCTION.
Variable p: program.
Hypothesis wt_p: wt_program p.
Let ge := Genv.globalenv p.

Lemma wt_instr_inv:
forall s f sp pc rs m i,
wt_state (State s f sp pc rs m) ->
f.(fn_code)!pc = Some i ->
exists env, wt_instr f env i /\ wt_regset env rs.