Seiberg-Witten curves with O7$^\pm$-planes

We construct Seiberg-Witten curves for 5d $\mathcal{N}=1$ gauge theories whose Type IIB 5-brane configuration involves an O7-plane and discuss an intriguing relation between theories with an O7$^+$-plane and those with an O7$^-$-plane and 8 D7-branes. We claim that 5-brane configurations with an O7$^+$-plane can be effectively understood as 5-brane configurations with a set of an O7$^-$-plane and eight D7-branes with some special tuning of their masses such that the D7-branes are frozen at the O7$^-$-plane. We check this equivalence between SU($N$) gauge theory with a symmetric hypermultiplet and SU($N$) gauge theory with an antisymmetric with 8 fundamentals, and also between SO($2N$) gauge theory and Sp($N$) gauge theory with eight fundamentals. We also compute the Seiberg-Witten curves for non-Lagrangian theories with a symmetric hypermultiplet, which includes the local $\mathbb{P}^2$ theory with an adjoint.