not a TensorRef == no indexes used
assertIndexesUsed(c)	${fixed} = {fixed}$ ${summed} = {summed}$ ${extra} = {extra}$ GOOD	time: 0.506000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
single TensorRef, fixed
assertIndexesUsed(c'_i', {fixed='_i'})	${{ fixed} _i} = {{ fixed} _i}$ ${summed} = {summed}$ ${extra} = {extra}$ GOOD	time: 0.855000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
assertIndexesUsed(c'_ij', {fixed='_ij'})	${{{ fixed} _i} _j} = {{{ fixed} _i} _j}$ ${summed} = {summed}$ ${extra} = {extra}$ GOOD	time: 0.705000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
assertIndexesUsed(c'^i_jk', {fixed='^i_jk'})	${{{{ fixed} ^i} _j} _k} = {{{{ fixed} ^i} _j} _k}$ ${summed} = {summed}$ ${extra} = {extra}$ GOOD	time: 0.764000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
single TensorRef, summed
assertIndexesUsed(c'^i_i', {summed='^i'})	${fixed} = {fixed}$ ${{ summed} ^i} = {{ summed} ^i}$ ${extra} = {extra}$ GOOD	time: 0.513000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
single TensorRef, mixed
assertIndexesUsed(c'^i_ij', {fixed='_j', summed='^i'})	${{ fixed} _j} = {{ fixed} _j}$ ${{ summed} ^i} = {{ summed} ^i}$ ${extra} = {extra}$ GOOD	time: 1.002000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
mul, fixed * summed
assertIndexesUsed(a'_i' * b'^j_j', {fixed='_i', summed='^j'})	${{ fixed} _i} = {{ fixed} _i}$ ${{ summed} ^j} = {{ summed} ^j}$ ${extra} = {extra}$ GOOD	time: 0.568000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
mul, fixed * fixed => summed
assertIndexesUsed(g'^im' * c'_mjk', {fixed='^i_jk', summed='^m'})	${{{{ fixed} ^i} _j} _k} = {{{{ fixed} ^i} _j} _k}$ ${{ summed} ^m} = {{ summed} ^m}$ ${extra} = {extra}$ GOOD	time: 0.591000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
add, nothing
assertIndexesUsed(a + b)	${fixed} = {fixed}$ ${summed} = {summed}$ ${extra} = {extra}$ GOOD	time: 0.122000ms stack: size: 0
add, fixed
assertIndexesUsed(a'_i' + b'_i', {fixed='_i'})	${{ fixed} _i} = {{ fixed} _i}$ ${summed} = {summed}$ ${extra} = {extra}$ GOOD	time: 0.287000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
assertIndexesUsed(a'_ij' + b'_ij', {fixed='_ij'})	${{{ fixed} _i} _j} = {{{ fixed} _i} _j}$ ${summed} = {summed}$ ${extra} = {extra}$ GOOD	time: 0.363000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
add, summed
assertIndexesUsed(a'^i_i' + b'^i_i', {summed='^i'})	${fixed} = {fixed}$ ${{ summed} ^i} = {{ summed} ^i}$ ${extra} = {extra}$ GOOD	time: 0.296000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
assertIndexesUsed(a'^i_i' + b'^j_j', {summed='^ij'})	${fixed} = {fixed}$ ${{{ summed} ^i} ^j} = {{{ summed} ^i} ^j}$ ${extra} = {extra}$ GOOD	time: 0.318000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
add, extra
assertIndexesUsed( a'_i' + b, {extra='_i'})	${fixed} = {fixed}$ ${summed} = {summed}$ ${{ extra} _i} = {{ extra} _i}$ GOOD	time: 0.214000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
assertIndexesUsed( a + b'_j', {extra='_j'})	${fixed} = {fixed}$ ${summed} = {summed}$ ${{ extra} _j} = {{ extra} _j}$ GOOD	time: 0.233000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
assertIndexesUsed( a'_i' + b'_j', {extra='_ij'})	${fixed} = {fixed}$ ${summed} = {summed}$ ${{{ extra} _i} _j} = {{{ extra} _i} _j}$ GOOD	time: 0.308000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
add, fixed + summed
assertIndexesUsed( a'^i_ij' + b'^i_ij', {fixed='_j', summed='^i'})	${{ fixed} _j} = {{ fixed} _j}$ ${{ summed} ^i} = {{ summed} ^i}$ ${extra} = {extra}$ GOOD	time: 0.359000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
assertIndexesUsed( a'^i_ij' + b'^k_kj', {fixed='_j', summed='^ik'})	${{ fixed} _j} = {{ fixed} _j}$ ${{{ summed} ^i} ^k} = {{{ summed} ^i} ^k}$ ${extra} = {extra}$ GOOD	time: 0.392000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
add, fixed + extra
assertIndexesUsed( a'_ij' + b'_kj', {fixed='_j', extra='_ik'})	${{ fixed} _j} = {{ fixed} _j}$ ${summed} = {summed}$ ${{{ extra} _i} _k} = {{{ extra} _i} _k}$ GOOD	time: 0.300000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
add, summed + extra
assertIndexesUsed( a'^i_ij' + b'^i_ik', {summed='^i', extra='_jk'})	${fixed} = {fixed}$ ${{ summed} ^i} = {{ summed} ^i}$ ${{{ extra} _j} _k} = {{{ extra} _j} _k}$ GOOD	time: 0.423000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
add, fixed + summed + extra
assertIndexesUsed( a'_ij^jk' + b'_ij^jl', {fixed='_i', summed='_j', extra='^kl'})	${{ fixed} _i} = {{ fixed} _i}$ ${{ summed} _j} = {{ summed} _j}$ ${{{ extra} ^k} ^l} = {{{ extra} ^k} ^l}$ GOOD	time: 0.448000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
TODO fixed and summed of add
TODO fixed and summed of add and mul
notice that the summed index is counted by the number of the symbol's occurrence, regardless of the lower/upper
this means the lower/upper of the summed will be arbitrary
assertIndexesUsed( a'^i' * b'_i' * c'_j', {fixed='_j', summed='^i'})	${{ fixed} _j} = {{ fixed} _j}$ ${{ summed} ^i} = {{ summed} ^i}$ ${extra} = {extra}$ GOOD	time: 0.339000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
assertIndexesUsed(a'^i' * b'_i' * c'_j' + d'^i' * e'_i' * f'_j', {fixed='_j', summed='^i'})	${{ fixed} _j} = {{ fixed} _j}$ ${{ summed} ^i} = {{ summed} ^i}$ ${extra} = {extra}$ GOOD	time: 0.401000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
assertIndexesUsed(a'^i' * b'_i', {summed='^i'})	${fixed} = {fixed}$ ${{ summed} ^i} = {{ summed} ^i}$ ${extra} = {extra}$ GOOD	time: 0.202000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
assertIndexesUsed(a'^i' * b'_i' + c, {summed='^i'})	${fixed} = {fixed}$ ${{ summed} ^i} = {{ summed} ^i}$ ${extra} = {extra}$ GOOD	time: 0.236000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
assertIndexesUsed(a'^i' * b'_i' + c'^i' * d'_i', {summed='^i'})	${fixed} = {fixed}$ ${{ summed} ^i} = {{ summed} ^i}$ ${extra} = {extra}$ GOOD	time: 0.189000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy