The phrase "an additional condition to" is correct and usable in written English.
It can be used when specifying an extra requirement or stipulation that must be met in a particular context.
Example: "The contract includes an additional condition to ensure that all parties comply with the new regulations."
Alternatives: "an extra requirement for" or "a supplementary condition for".
To obtain a unique solution, one must impose an additional condition to reduce the one-parameter family of solutions by constraining Φ.
We notice that we need to add an additional condition to guarantee the uniqueness.
Keith [67] suggested including an additional condition to enable solution of the system of equations: the sum of ring bond charges should be zero.
Therefore, we need an additional condition to obtain balance between collective production and consumption rates for S23.
We added an additional condition to include the uneven number of inhibiting interactions in the path (that's required for the path to have activating effect).
"The administration does not support the attachment of any additional conditions to the payment of these arrears," Philip Reeker, a State Department spokesman, said today.
Furthermore, overlapping classes, namely the edge and perforated classes, need an additional condition similar to the one for interior to exclude areas included in undetermined class.
To address this possibility, the same observers completed an additional condition, identical to the motion condition from Experiment 2 except that the test waveform was removed from the display during the inter-stimulus-interval (ISI) after motion offset (see Figure 4).
The samples investigated in this work are much smaller in diameter than the radius of the cylinder, because an additional condition is to confine the sample near the cylinder axis for focusing.
But if people were unmarried and not in civil partnerships the non-tenant had to meet an "additional condition" in order to succeed the tenant.
Accordingly an additional condition is needed to define a continuum.
