Concrete sparse-store arithmetic instruction kernel #
This surface exposes the first complete instruction-level composition in the RAM-to-TM direction: two canonical operands are combined by a width-efficient binary machine and the result is committed by the fixed encoded-store update controller. A redirected form writes the new store to a fresh work buffer.
Uniform framed contract for the selected arithmetic operation.
Width-efficient arithmetic followed by a semantics-exact sparse write.
Redirect the updated encoded store into a fresh last work tape while the real output remains the standard blank parked tape.
Arithmetic and sparse update are both one-way-output machines.
Two direct sparse-register reads, arithmetic, and the destination write
realize one complete direct add, sub, or mul instruction.
Direct arithmetic instruction simulation never moves the output head left.
Every prefix of a direct arithmetic instruction respects the coarse initial-space-plus-total-time auxiliary-space envelope.
A fixed-address lookup followed by a loaded runtime-address lookup and
sparse update realizes one indirect load.
Indirect-load simulation never moves the output head left.
Every indirect-load prefix respects the coarse initial-space-plus-total-time auxiliary-space envelope.
Immediate-value and destination synthesis followed by sparse update
realizes one imm instruction.
Immediate-instruction simulation never moves the output head left.
Every immediate-instruction prefix respects the coarse initial-space-plus-total-time auxiliary-space envelope.
Two direct lookups followed by framed binary copies into the update ABI
realize one indirect store.
Indirect-store simulation never moves the output head left.
Every indirect-store prefix respects the coarse initial-space-plus-total-time auxiliary-space envelope.
Reset and replace a canonical binary program counter by a fixed literal.
Conditional-zero control realizes sparse jz and restores its loaded
operand to the clean lookup ABI.
Unconditional control replaces the program counter by its jump target.
Halt is an exact no-op at the clean control boundary.
Program-counter replacement never moves the output head left.
Conditional-zero control never moves the output head left.
Unconditional jump control never moves the output head left.
Halt control never moves the output head left.
Every conditional-zero prefix respects the coarse initial-space-plus-total-time auxiliary-space envelope.
Every unconditional-jump prefix respects the coarse initial-space-plus-total-time auxiliary-space envelope.
Every halt prefix respects its one-step auxiliary-space envelope.