not a TensorRef == no indexes used
assertIndexesUsed(c)	${fixed} = {fixed}$ ${summed} = {summed}$ ${extra} = {extra}$ GOOD	time: 0.540000ms 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: 0.594000ms 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: 0.854000ms 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: 0.915000ms 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: 0.447000ms 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: 0.654000ms 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: 0.551000ms 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: 0.719000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy
add, nothing
assertIndexesUsed(a + b)	${fixed} = {fixed}$ ${summed} = {summed}$ ${extra} = {extra}$ GOOD	time: 0.127000ms stack: size: 0
add, fixed
assertIndexesUsed(a'_i' + b'_i', {fixed='_i'})	${{ fixed} _i} = {{ fixed} _i}$ ${summed} = {summed}$ ${extra} = {extra}$ GOOD	time: 0.601000ms 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: 0.536000ms 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: 0.423000ms 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: 0.338000ms 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: 0.279000ms 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: 0.314000ms 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: 0.228000ms 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: 0.294000ms 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: 0.534000ms 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: 0.571000ms 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: 0.610000ms 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: 0.689000ms 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: 0.610000ms 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: 0.637000ms 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: 0.265000ms 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: 0.227000ms stack: size: 7 Init Prune Expand Prune Factor Prune Tidy