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Proof step 26 from proof validrefnotnull-union-at-right (previous step)

is_obj(str, r, st0), st0[r -- _type] .type = mkclasstype(class0), mkfs(class1, ty, fieldvar) ' ∈ instfields(class), class0 ≤ class, is_valid_ref(str, r, st0) ⊦ r = jvmref, st[r -- mkfs(class1, ty, fieldvar) '] = noval, ∃ fs. fs ' ∈ instfields(st0[r -- _type] .type .class) ∧ is_referencevalue(st0[r -- fs ']) ∧ st0[r -- fs '] .refval ≠ jvmref ∧ (¬ st0[st0[r -- fs '] .refval -- _type] .type ≤ fs .type ∨ junkref(str, st0[r -- fs '] .refval, st0)), r -- mkfs(class1, ty, fieldvar) ' ∈ st0, (is_reftype(ty) ∨ ty = abstract_type) ∧ noval .refval ≠ jvmref

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Proof step 25:
st0[r -- _type] .type = mkclasstype(class0), class0 ≤ class, mkfs(class1, ty, fieldvar) ' ∈ instfields(class), is_obj(str, r, st0) ⊦ st[r -- mkfs(class1, ty, fieldvar) '] = noval, r = jvmref, r -- mkfs(class1, ty, fieldvar) ' ∈ st0, (is_reftype(ty) ∨ ty = abstract_type) ∧ noval .refval ≠ jvmref, ∃ fs. fs ' ∈ instfields(class0) ∧ is_referencevalue(st0[r -- fs ']) ∧ st0[r -- fs '] .refval ≠ jvmref ∧ (¬ st0[st0[r -- fs '] .refval -- _type] .type ≤ fs .type ∨ junkref(str, st0[r -- fs '] .refval, st0))

Rule argument

[emptyarg]

Additional information

[[CONCRETESIMPRULES : ([CSIMPSEQ : ⊦ mkclasstype(class) .class = class], [CSIMPSEQ : ⊦ is_obj(str, r, st) → is_valid_ref(str, r, st)])]]